Isolated nucleic acid molecule which codes for a 32 kDa protein having 11-CIS retinol dehydrogenase activity, and which associates with p63, a portion of a retinol binding protein receptor

ABSTRACT

In accordance with this invention, an RPE cell membrane associated protein which has a molecular weight of about 32 kd, as determined by SDS-PAGE, has been discovered. This protein, referred to an “p32,” forms an oligomeric protein complex with the previously characterized p63 protein, a component of the membrane receptor for RBP. A nucleic acid molecule which codes for the p32 protein has also been isolated and sequence analysis shows that the p32 protein belongs to the family of short chain alcohol dehydrogenases, and exhibits 11-cis retinol dehydrogenase activity, the enzyme which catalyzes conversion of 11-cis-retinol into 11-cis retinaldehyde.

[0001] RELATED APPLICATIONS

[0002] This application is a continuation-in-part of copending application Serial Number 08/375,962, filed Jan. 20, 1995, which is itself a continuation in part of copending application, Serial No. 08/258,418 filed Jun. 10, 1994. Both applications are incorporated by reference.

FIELD OF THE INVENTION

[0003] This invention relates to a protein having 11-cis retinol dehydrogenase activity, and which forms a complex with a specific portion of a membrane receptor for plasma retinol-binding protein (RBP) expressed, e.g., in retinal pigment epithelium (RPE), and more specifically a 32 kDa protein having 11-cis retinol dehydrogenase activity, which forms a complex with a 63 kDa RBP-binding membrane protein. The invention also involves isolation of the 32 kDa protein (p32), as well as nucleic acid molecules coding for p32 or complimentary to coding sequences therefor, in addition to various applications of these materials.

BACKGROUND AND PRIOR ART

[0004] Retinoids (vitamin A-derivatives) have important physiological functions in a variety of biological processes. During embryonic growth and development, as well as during growth and differentiation of adult organisms, retinoids act as hormones and participate in the regulation of gene expression in a number of cell types. See Lied et al. Trends Genet., 17:427-433 (1992). It is believed that the effects of these molecules are mediated through two classes of nuclear ligand-controlled transcription factors, the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs), Benbrook et al., Nature, 333:669-672 (1988); Brand et al., Nature, 332:850-853 (1988); Giguere et al., Nature, 330:624-629 (1987); Mangelsdorf et al., Nature, 345:224-229 (1990); Mangelsdorf, et al. Genes Dev. 6:329-344 (1992); Petkovich et al. Nature 330:440-450 (1987); and Zelent et al., Nature 339:714-717 (1989).

[0005] Apart from their role as hormones in cellular growth and differentiation, retinoids are also involved in the visual process as the stereo isomer 11-cis retinaldehyde of retinaldehyde is the chromophore of the visual pigments. See, e.g. Bridges, The Retinoids, Vol. 2, pp 125-176, Academic Press, Orlando, Fla., (1984).

[0006] Under normal physiological conditions most cells, both ocular and non-ocular, obtain all-trans retinol as their major source of retinoids. Despite the many different metabolic events taking place in different tissues, it is known that a common extracellular transport machinery for retinol has evolved. Specifically, in plasma, retinol is transported by plasma retinol binding protein (RBP). See Goodman et al., The Retinoids, Academic Press, Orlando Fla., Volume 2, pp. 41-88 (1984). The active derivatives of retinol, i.e., retinoic acid in non-ocular tissues and mostly 11-cis retinaldehyde for ocular tissues, are generated by cellular conversion of trans-retinol, using specific mechanisms. To date, none of these mechanisms have been fully defined at the molecular level and several of the enzymes involved have only been identified by enzymatic activities. See Lion et al., Biochem. Biophys. Acta. 384:283-292 (1975); Zimmermann et al., Exp. Eye Res. 21:325-332 (1975); Zimmermann, Exp. Eye Res. 23:159-164 (1976) and Posch et al., Biochemistry 30:6224-6230 (1991).

[0007] Polarized retinal pigment epithelial cells (polarized RPE) are unique with regard to retinoid uptake since all-trans retinol enters these cells via two different mechanisms. Retinol accumulated from RBP is taken up through the basolateral plasma membrane, while all-trans retinol, presumably taken up from the interstitial retinol-binding protein (IRBP) following bleaching of the visual pigments, may enter through the apical plasma membrane. See Bok et al., Exp. Eye Res. 22:395-402 (1976); Alder et al., Biochem. Biophys. Res. Commun. 108:1601-1608 (1982); Lai et al., Nature 298:848-849 (1982); and Inu et al., Vision Res. 22:1457-1468 (1982).

[0008] The transfer of retinol from RBP to cells is not fully understood. In a number of cell types, including RPE, specific membrane receptors for RBP have been identified. This is consistent with a receptor-mediated uptake mechanism for retinol. For example isolated retinol binding protein receptors, nucleic acid molecules coding for these receptors and antibodies binding to the receptor have been taught, in references relating to the first of the two mechanisms. See Bavik et al., J. Biol. Chem. 266:14978-14985 (1991); Bavik, et al. J. Biol. Chem. 267:23035-23042 1992; Bavik et al., J. Biol. Chem. 267:20540-20546 (1993); and copending U.S. application Ser. No. 083,539 and International Publication WO 93/23538, all of which are incorporated by reference herein. See also Heller, J. Biol. Chem. 250:3613-3619 (1975); and Bok et al., Exp. Eye Res. 22:395-402 (1976).

[0009] Retinol uptake on the apical side of the RPE for the regeneration of 11-cis retinaldehyde, is less well characterized. Regardless of the origin of all-trans retinol, however, the synthesis and apical secretion of 11-cis retinaldehyde seems to be the major pathway for accumulated retinol in the RPE. At present, it is not known whether similar mechanisms are used with regard to cellular retinol uptake through the basolateral and the apical plasma membranes. Available data do show that functional receptors for RBP are exclusively expressed on the basolateral plasma membrane of RPE-cells. Bok et al., Exp. Eye Res. 22:395-402 (1976).

[0010] It is also known that RPEs express a 63 kDa protein (p63). This molecular weight, and all others, is by reference to SDS-PAGE, unless stated otherwise. It has also been shown by chemical cross-linking that this protein may be part of an oligomeric protein complex which functions as a membrane receptor for plasma retinol-binding protein (RBP) in RPEs, or a component of the retinoid uptake machinery in RPE cells. See Bavik et al, J. Biol. Chem. 266:14978-14875 (1991); Bavik et al., J. Biol, Chem. 267:23035-23042 (1992), U.S. patent application Ser. No. 083,539 and PCT application WO93/23538. The p63 protein has been isolated and the corresponding cDNA cloned. See Bavik et al., J. Biol. Chem. 267:20540-20546 (1993). Nothing in these references suggests the existence of the protein which is a feature of this invention.

SUMMARY OF THE INVENTION

[0011] In accordance with this invention, RPE membrane associated proteins which have a molecular weight of about 32 kd, as determined by SDS-PAGE, are disclosed. These proteins, referred to as “p32,” form oligomeric protein complexes with the previously characterized p63 protein, a component of the membrane receptor for RBP. Also disclosed are nucleic acid molecules which code for the p32 protein. Sequence analysis shows that the p32 protein belongs to the family of short chain alcohol dehydrogenases, and exhibits 11-cis retinol dehydrogenase activity, the enzyme which catalyzes the stereospecific conversion of 11-cis-retinol into 11-cis retinaldehyde in the presence of cofactor NAD+.

[0012] As will be shown, p32 has many important uses. For example, owing to its membrane bound 11-cis-retinol dehydrogenase activity, which catalyzes the conversion of 11-cis-retinol to 11-cis-retinaldehyde, a major metabolic step in retinoid metabolism in RPE-cells, retinoid accumulation and metabolism which may lead to retinitis pigmentosa, may be directly or indirectly tied to the presence of p32, and/or its activation or inhibition. As p32 has also been found to be a member of the short chain alcohol dehydrogenase super family, many known alcohol dehydrogenase inhibitors (and activators) are available to develop activity assays, and thus diagnostic materials for retinol uptake, and ocular retinoid metabolism.

[0013] Particular features of the invention include nucleic acid molecules which encode mammalian forms of these proteins, such as human, bovine, and murine forms. Also a part of the invention are probes, based upon extended sequences as described herein.

[0014] These and other aspects of this invention are more fully discussed in the following specification with accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

[0015]FIG. 1A shows SDS-PAGE analysis of radiolabeled protein from RPE-membranes and immunoprecipatation with mAb A52 against p63.

[0016]FIG. 1B shows SDS-PAGE analysis of RPE-membrane proteins bound and eluted through an mAb A52 immunoaffinity column, and the presence of p32 in the eluted fraction from the immunoaffinity column.

[0017]FIG. 2A shows visualization via agarose gel electrophoresis of a 61 bp PCR-amplified fragment using oligonucleotide mixtures OM1 and OM3, both derived from peptide 321 deduced from partial amino acid sequence determination of trypsin digested p32.

[0018]FIG. 2B shows visualization of a 330 bp PCR-amplified fragment using oligonucleotide mixtures OM2 and OM3, derived from peptides p323 and p321, respectively, as deduced from partial amino acid sequence determination of trypsin digested p32.

[0019]FIG. 3 illustrates the nucleotide sequence of pλ321 and the deduced amino acid sequence of p32, with the partial amino acid sequences determined from peptides isolated from trypsin digested p32.

[0020]FIG. 4 illustrates amino acid sequence alignments of p32 and some related proteins belonging to the family of short-chain alcohol dehydrogenases.

[0021]FIG. 5 illustrates analysis of the amino acid sequence of p32.

[0022]FIG. 6 illustrates membrane interaction of p32 synthesized in vitro.

[0023]FIG. 7 illustrates the restricted expression of transcripts corresponding to p32.

[0024]FIG. 8A illustrates expression of p32 in transfected cells for further enzymatic activity analysis of 11-cis retinol dehydrogenase activity.

[0025]FIG. 8B illustrates the expression of 11-cis retinol dehydrogenase activity in the presence of NAD+ as indicated by the formation of 11-cis retinaldehyde.

[0026]FIG. 8C illustrates the lack of 11-cis-retinol dehydrogenase activity in the presence of cofactor NADP.

[0027]FIG. 8D illustrates control cells not expressing p32 which lack the ability to oxidize 11-cis-retinol into 11-cis-retinaldehyde.

[0028]FIG. 9 shows the structure of the human 11-cis-retinol dehydrogenase gene.

DETAILED DISCUSSION OF PREFERRED EMBODIMENTS

[0029] It is known that plasma retinol binding protein (RBP) can be chemically cross-linked to a high molecular weight complex of a 63 kDa protein (p63) receptor of retinal pigment epithelium membranes (RPE), forming an RBP-RBP receptor complex with elution properties of globular proteins of similar sizes having apparent molecular weights of approximately M_(r) 150,000 and 450,000. See Bavik et al, J. Biol. Chem. 266:14978-14875 (1991), and Bavik et al., J. Biol. Chem. 267:23035-23042 (1992). The protein responsible for binding of REP, expression of which is restricted to RPE, has been identified as a 63 kDa protein (p63). Through the generation of a monoclonal antibody A52 (mAb A52) to the 63 kDa protein which binds the RBP-RBP receptor complex and p63, and immunoaffinity chromatographic analysis, it has been found that the majority of p63 elutes as a monomer, with a significant portion of the protein found in positions corresponding to higher molecular weight species. This indicates that p63 exists in an oligomeric protein complex with other protein components. Bavik et al., J. Biol. Chem. 266:14978-14985 (1991), and Bavik et al, J. Biol. Chem. 267:23035-23042 (1992). Therefore, the following procedure was carried out to investigate the molecular characteristics of such oligomeric protein complexes, and whether p63 forms a complex with other proteins specific to RPE. The results show that a 32 kDa membrane associated protein (p32) indeed forms a complex with p63.

EXAMPLE 1

[0030] Bovine RPE-cells were isolated and membrane fractions were prepared as described in Bavik et al, J. Biol. Chem. 266:14978-14875 (1991) incorporated by reference. RPE-membrane proteins were then solubilized in phosphate-buffered saline (PBS)(20 mM sodium phosphate, pH 7.2, containing 150 mM NaCl), containing 1% 3-[(3-cholamido-propyl)-dimethylammonio]-1-propane sulfonic acid (CHAPS) at 1 mg of total membrane protein/ml of buffer. Remaining material was removed by ultracentrifugation at 100,000×g for 1 hour. Next, 500 ul aliquots of the solubilized membranes were subjected to gel filtration on a Sepharose 6 column equilibrated in PBS containing 1% CHAPS. The column was operated at a flow rate of 0.2 ml/min and 500 ul fractions collected. Proteins eluted in fractions corresponding to globular proteins of M_(r) 150,000 to 400,000 were then radiolabelled with Na¹²⁵I using the well-known Chloramin T procedure. Non-incorporated ¹²⁵I was removed by gel filtration on Sepahadex G-25 packed in a Pasteur pipette.

[0031] Aliquots of the radiolabelled proteins were then diluted in PBS containing 1% CHAPS and 1% bovine serum albumin and subsequently subjected to immunoprecipitation using mAb A52, which specifically binds to p63 (5 ug per incubation) or by using two polyclonal rabbit antisera to p63 (3 ul of serum per incubation) See Bavik et al., J. Biol. Chem. 267:23035-23042 (1992). Non-specific immunoprecipitation was monitored in parallel incubations using an unrelated mAb and preimmune rabbit serum. Fifty ul of a 50% slurry of protein A-Sepharose was added to the incubations for 30 minutes. The beads were subsequently carefully washed with PBS containing 1% CHAPS and the eluted material then prepared for SDS-PAGE analysis, was carried out according to the classic method of Blobel et al. J. Cell. Biol. 67:835-851 (1975).

[0032] Referring now to FIG 1A, autoradiograms of the SDS-PAGE gels showed that both types of reagents reacted with p63, whereas the unrelated mAb or preimmune rabbit serum did not precipitate p63. In all lanes containing immunoprecipitated p63 there was an enrichment of a M_(r) 32,000 protein. Since both mAb A52 and the rabbit antisera to p63 are highly specific for p63 (See, for example, Bavik et al., J. Biol. Chem. 267:23035-23042 (1992)), it can be concluded that the M_(r) 32,000 protein (p32) coprecipitated in the aforesaid analysis by binding to p63. The analysis also identified a double band of M_(r) 50,000-52,000 which precipitated along with p32 and p63 (FIGS. 1D, E).

EXAMPLE 2

[0033] Experiments were then carried out to identify p32. Advantage was taken of the fact that p32 specifically interacts with p63 as shown supra. Thus, detergent solubilized RPE-membrane proteins were passed over an immunoaffinity column containing mAb A52. Referring now to FIG. 1B, lane b, following a washing procedure, bound proteins were eluted at high pH in a CHAPS-containing buffer, and SDS-PAGE analysis and Coomassie staining of the eluted fractions revealed p63 to be specifically retained and eluted from the immunoaffinity column. Further, a weekly stained band corresponding to p32 could be visualized in the eluate from the A52 column. As shown in FIG. 1B, a comparison of the total protein profile of solubilized RPE membranes and the eluted fraction from the A52 column show that the p32 protein is not efficiently retained therein. However, the appearance of p32 in the eluted fraction from the A52 column, but not in the eluted fraction from the column containing an unrelated Ig, indicate a specific interaction of p32 with p63. This result is consistent with previous immunoprecipitation data, and shows that p32 is complexed to p63 and is retained on the immunoaffinity column due to this complex formation.

[0034] Following identification of p32 as a component of a complex with p63 in RPE-membranes, the p32 protein itself was isolated by SDS-PAGE of eluted fractions of solubilized RPE-membranes from the A52 immunoaffinity column, as set forth below in Example 3.

EXAMPLE 3

[0035] RPE-membranes were solubilized in PBS containing 1% CHAPS as set out above and then incubated with mAb A52 Ig coupled to CNBr-activated Sepharose 4B beads (Pharmacia) in a Bio-Rad poly prep column (Bio-Rad) by end-over-end rotation at +4° C. Following a 2 hour incubation, the beads were allowed to settle and the column was quickly washed with 5 column volumes of PBS containing 1% CHAPS. Bound proteins were then eluted with 50 mM triethanolamine buffer (pH 11.2) containing 1% CHAPS. The pH of the eluate was quickly adjusted to 8.0 by the addition of 1 M Tris-HCl buffer containing 1% CHAPS. The eluted fractions were subjected to SDS-PAGE, and the separated proteins then visualized by Coomassie Blue staining. A band corresponding to p32 (SDS-PAGE, 32 kDa), was found.

[0036] To determine the primary structure of p32, partial amino acid sequence analysis of the isolated protein was undertaken by first cutting out a portion of the aforesaid Coomassie stained band corresponding to approximately 2-5 ug of the 32 kDa protein, then lyophilizing the gel piece to dryness. The gel was rehydrated in buffer containing modified trypsin and incubated to generate various peptides for extraction and analysis. A preferred procedure is set forth below in Example 4.

EXAMPLE 4

[0037] Coomassie stained bands containing the p32 protein from Example 3 were excised and treated according to Rosenfeld et al. Anal. Biochem. 15:173-179 (1992) with minor modifications. The gel pieces were washed twice for 30 min at 30° C. with 100 ul of 0.2 M ammonium bicarbonate buffer containing 50% acetonitrile and thereafter completely dried under a stream of nitrogen. The gel pieces were subsequently rehydrated with 5 ul of 0.2 M ammonium bicarbonate buffer containing 0.02% Tween 20 and 0.5 ug of modified trypsin. Trypsin was added from a stock solution prepared in 1 mM HCl. Rehydration was continued by the addition of 5 ul portions of the 0.2 M ammonium bicarbonate buffer until the gel pieces rehydrated to their original sizes. The rehydrated gel pieces were then incubated overnight at 30° C. Protease activity was inhibited by the addition of trifluoroacetic acid (TFA) to a final concentration of 1%. The supernatant was recovered and combined with two extracts made with 150 ul of 0.1% TFA in 60% acetonitrile. The organic phase was reduced and the digest was subjected to HPLC using a reverse phase mRPC C2/ C18 SC 2.1/10 column operated in a SMART system. The sample was eluted with a gradient of acetonitrile in 0.065% TFA and fractions containing discrete peptides were collected using the automatic peak fractionation option. Five of the identified peptides were selected for amino acid sequence analysis using an ABI 470A sequencer equipped with a model 120A PTH analyzer (applied Biosystems Inc. Foster City, Calif.). The results are set forth below in Table 1. TABLE 1 Amino acid sequences determinations of five peptides isolated from trypsin digested p32. p321 L-V-E-A-V-L-A-E-V-L-P-K-P-A-Q-T-V-A (SEQ ID NO:1)    (D)^(a)      (W)                 (Y) P322 Y-S-P-G-W-D-A-K (SEQ ID NO:2) P323 T-P-V-T-N-L-E-T-L-E-D-T-L-Q-A (SEQ ID NO:3) P324 D-V-A-P-F-G-V (SEQ ID NO:4) P325 L-H-T-T-L-L-D-V-T-D-P-Q-S-I (SEQ ID NO:5)

EXAMPLE 5

[0038] Four degenerate oligonucleotide mixtures derived from peptides p321 and p323 were synthesized using well-known techniques. The two sense mixtures (OM1 and OM3) were derived from the N-terminal amino acids 1-5 of p321 and 2-6 of p323. The antisense mixtures (OM2 and OM4) were derived from amino acids 12-17 of p321 and 10-15 of p323. All nucleotide mixtures were synthesized with a 4 bp 5′ extension and an Eco RI-site for subsequent cloning of the PCR products. The sequences of the oligonucleotide mixtures are set out below in Table 2, and the Eco RI-site is underlined. Positions containing all four bases are marked N. TABLE 2 OM1: ACGT GAA TTC TN GTN GARGCN GT (SEQ ID NO:6) OM2: ACGT GAA TTC AC NGTYTG NGC NGGYTT (SEQ ID NO:7) OM3: ACGT GAA TTC CCN GTN ACN AAYYT (SEQ ID NO:8) OM4: ACGT GAA TTC GCYTG NARNGTRTCYTC (SEQ ID NO:9)

[0039] Single stranded “complementary” cDNA from reverse transcribed RPE mRNA and four combinations of the above-described degenerate nucleotide mixtures were employed in polymerase chain reactions (PCR) using a standard procedure. Following the amplification procedure, aliquots of the PCR reaction products were analyzed by agarose gel electrophoresis. The procedure is set out below in Example 6.

EXAMPLE 6

[0040] To carry out the PCR amplifications, first strand cDNA was synthesized by standard procedures using avian myelostosis virus reverse transcriptase. Twenty ug of total RNA from isolated RPE-cells were used and the reaction was primed with oligo (dT) 15. Aliquots corresponding to 2 ug of total RNA was used in each subsequent PCR reaction. The PCR reactions were performed using a final concentration of 0.5 uM of the oligonucleotide mixtures in a 100 ul reaction. Taq polymerase was used. Following 30 cycles (2 minute at 95° C., 1 minute at 55° C. and 2 minute at 72° C.), aliquots of the reactions were analyzed on 4% GTG agarose gel containing 5 ug/ml of ethidium bromide.

[0041] As shown in FIG. 2A, amplifications using the oligonucleotide mixtures OM1 and OM2, both derived from peptide p321, resulted in an amplified 61 bp fragment. Amplifications using mixtures OM3-OM4 and OM1-OM4 failed to yield any products. Finally, as shown in FIG. 2B, amplification using OM3-OM2 resulted in an amplified 330 bp fragment.

[0042] Subsequent sequence analysis of the 61 bp and 330 bp fragments confirmed that cDNA sequences have been amplified which corresponded to the peptide sequences generated in the previous amino acid sequence analysis. Differences between the deduced amino acid sequences from amplified PCR fragments and the generated amino acid sequence of peptide p321 indicates the generation of specific probes suitable for the isolation of full length cDNA clones encoding p32.

[0043] To isolate a full length cDNA clone, an RPE-specific lambda ZAP-II cDNA library was screened with the 330 bp fragment as the probe. Five independent lambda clones were isolated from approximately 200,000 clones, and subcloned by in vivo excision. The cDNA clone pλ321 contained the longest insert, (approximately 1.1 Kb), and was selected for use in further studies.

[0044] Both strands of pλ321 were fully sequenced with the insert being 1104 bp long, excluding linkers used to prepare the cDNA library. The procedure is set out below in Example 7.

EXAMPLE 7

[0045] The amplified products using OM1-OM2 (61 bp) and OM3-OM2 (330 bp) were digested with EcoRI, gel purified and cloned into EcoR1-cut vector pBS. The ³²P-labelled 330 bp fragment was used to screen a RPE-specific λZAP II cDNA library as previously described by Bavik et al., J. Biol. Chem. 267:20540-20546 (1993), incorporated by reference. Five positive λ clones were isolated and the inserts were subcloned in pBluescript by in vivo excision following the manufacturer's instructions. Clone pλ321 contained an insert of 1.1 Kb, and both strands were fully sequenced using Sequenase with T3, T7 or M13 universal primers or with internal primers.

[0046] The nucleotide sequence of pλ321 and the predicted amino acid sequence of p32 are shown in FIG. 3 and SEQ ID NO: 10. Nucleotides are numbered on the left and amino acid residues on the right. Amino acid 1 is initial methionine (“Met”).

[0047] As shown in FIG. 3, the 1.1 kbp insert contains one long open reading frame encoding 318 amino acid residues with a calculated mass of 35,041D. The first methionine residue lies in a good context according to the Kozak rules for transcription initiation and is likely to be the initiation codon. See Kozak, Cell, 44:283-292 (1986). This inference is strengthened by the fact that in vitro translation of synthetic mRNA transcribed from pλ321 gives rise to a M_(r) 32,000 protein (SDS-PAGE analysis), as set out below, but there is no stop codon in frame in the upstream 35 bp 5′-untranslated region of the cDNA. As also shown in FIG. 3, the 100 bp 3′-untranslated region ends with a putative polyA-tract, and a polyA-signal was identified in the upstream sequence (bp 1104-1110).

[0048] The deduced amino acid of pλ321 and the amino acid sequences of the five generated tryptic peptides (Table 1) differ in only 3 positions out of the 62 residues available for a comparison. All 3 differences are found in the peptide p321 but the nucleotide sequence in this region of a second cDNA clone (pλ324) is identical to that of pλ321. This indicates that the amino acid sequence determination of peptide p321 was probably incorrect although it cannot be excluded that the differences are due to the presence of different alleles of p32. These data demonstrate that pλ321 contains the complete coding region of p32.

[0049] Again, referring to FIG. 3, a consensus sites for N-linked glycosylation (amino acid residues N-I-T) could be found in the deduced amino acid sequence at position 160-162.

[0050] Additionally, it has been found that p32 shows sequence similarities to short-chain alcohol dehydrogenases. Referring now to FIG. 4 a search through the Swissprot protein data base revealed that p32 is structurally related to several previously sequenced proteins. It is most closely related to a mitochondrial matrix dehydrogenase, the D-β-hydroxybutyrate dehydrogenase (BDH) Churchill et al; Biochem. 31:3793-3799 (1992) and shows less but significant similarities to two other proteins, the 3-oxoacy[acyl carrier protein] reductase from E. coli (Rawlings et al., J. Biol. Chem. 267-5751-5754 (1992)) and the human estradiol 17 β-dehydrogenase (Peltoketo et al., FEBS Lett., 239:73-77 (1988) and Leu et al., Mol. Endocrinol. 3:1301-1309 (1989)). All the related proteins fall into the protein super-family of short-alcohol dehydrogenases. This protein superfamily comprises approximately 50 different proteins (Persson et al, Eur. J. Biochem, 200:537-593 (1991)). The overall sequence homology between p32 and BDH is around 39%. The level of homology to the E. coli reductase and to the estradiol 17-β-dehydrogenase is lower (31% and 33%, respectively).

[0051] Optimal multiple alignment identified several conserved regions shared by p32 and the most closely related proteins (boxed areas in FIG. 4). The first region involving residues 63-69 (using the numbering in FIG. 4) which displayed the conserved motif G-X-X-X-G-X-G is believed to be the binding site for cofactors NAD, NADP or its reduced forms. Another conserved region is found between residues 148-153 (consensus sequence L-V-N-N-A-G) but no functional characteristics have yet been attributed to that sequence motif. The sequence motif Y-X-X-X-K, thought to be the active site, is the most highly conserved motif in short-chain alcohol dehydrogenases and is present in p32 residues 175-179 See Persson et al., Eur. J. Biochem, 200:537-593 (1991). These similarities demonstrate that p32 exhibits several features of a functional short-chain alcohol dehydrogenase.

[0052] As shown in FIG. 5, hydropathy analysis of the amino acid sequence of p32 reveals several hydrophobic stretches, indicating that p32 is a membrane-associated protein. The first 18 amino acids are hydrophobic, and this region has characteristics of a classical signal sequence. However, a consensus site for signal peptidase cleavage could not be identified. See Von Heijne, Nucl. Acid Res., 14z4683-4690 (1986). The amino acids between residues 130 to 150 are hydrophobic and there is a relatively long hydrophobic stretch near the C-terminus of the protein. Thus, p32 displays several hydrophobic regions which are potential membrane spanning segments. In light of the homology to the family of short-chain alcohol dehydrogenases as shown above, it is likely that the central hydrophobic region of p32 (residues 130-150) is not used as a membrane anchor. Instead, both the N-terminal and the C-terminal regions are potential membrane anchoring domains.

[0053] To determine the mode of interaction of p32 with membranes, p32 was synthesized by in vitro translation using a reticulocyte lysate system with mRNA transcribed from linearized pλ321. The procedure is set out in Example 8 infra.

EXAMPLE 8

[0054] Expression of P32 by in Vitro Translation

[0055] In vitro transcribed mRNA encoding p32 was synthesized from linearized Pλ321 using T7 RNA polymerase. In vitro translation reactions were carried out using nuclease treated rabbit reticulocyte lysate following the manufacturer's instructions. Fifty ng of mRNA was included in each reaction, with or without the addition of dog pancreatic microsomes. To isolate membrane inserted p32, the microsomes were collected by centrifugation at 12,000×g for 10 min at 4° C. The microsomes were carefully resuspended in PBS and recentrifugated.

[0056] As shown in FIG. 6, translation in the presence of dog pancreatic microsomes showed that p32 becomes almost quantitatively membrane associated and migrates as a M_(r) 32,000 species in SDS-PAGE. Translation in the absence of acceptor membranes similarly yields a M_(r) 32,000 protein. These data indicate that the N-terminal hydrophobic sequence acts as a signal sequence but it is not removed by the signal peptidase, and such supports the previous observation that a consensus site for signal peptidase cleavage could not be identified in the deduced primary sequence.

[0057] The tissue expression of p32 was analyzed by Northern blotting analyses using total RNA isolated from bovine RPE, liver, kidney, adrenal, lung, testis, brain and muscle. The procedure is set out in Example 9.

EXAMPLE 9

[0058] Northern Blot Analyses

[0059] Twenty ug of total RNA isolated from a number of tissues was electrophoresed on a 1% agarose under denaturing conditions and transferred to a Hybond-N nylon filter. The filter was hybridized with ³²P-labelled full length cDNA encoding p32 under stringent conditions. The details of the isolation of total RNA, hybridization conditions and washing procedure were identical to those previously described in Bavik, et al., J. Biol. Chem. 267:20540-20546 (1993).

[0060] Hybridization at high stringency with the 1.1 Kb insert of pλ321 as the probe, revealed abundant expression of transcripts corresponding to p32 only in RPE but not at a detectable level in several other tissues. The size of the major transcript was 1.4 kb but other less abundant transcripts could be visualized after prolonged exposure of the filters both in RPE as well as in other tissues.

EXAMPLE 10 Expression of p32 in COS-cells and Enzymatic Analysis of the Properties of Recombinant p32.

[0061] p32 was first expressed in COS-cells using a eukaryotic expression vector, and then microsome fractions from transfected cells and control cells were subjected to immunoblotting analysis to verify the expression of p32 at the desired levels, as follows:

[0062] Specifically, the EcoRI insert of p λ 321 was cloned into the EcoRI-digested eucaryotic expression vector pSG5. See Green et al., Nucl. Acid Res. 16:39 (1988). COS-cells were maintained in Dulbecco's minimal essential medium supplemented with 10% fetal bovine serum, 2mM glutamine and antibiotics. The cells were seeded into 60 mm petri dishes (4×10⁵ cells per dish) and transfected with 5 ug of plasmid per dish using DEAE dextran. Control cells were transfected with equal amounts of the parental vector alone. After treatment with 10% DMSO for 2 minutes, the cells were incubated for 72-96 hours, and then harvested by scraping the dishes with a rubber policeman, and the cells thereafter collected by low speed centrifugation. The collected cell pellets were next resuspended in hypotonic buffer (10 mM Tris-HCl, pH 7.5, containing 1mM phenyl-methylsufonyl fluoride), put on ice for 20 minutes, and then homogenized using a Dounce homogenator. Unbroken cells and debris were removed by centrifugation (3000×g)for 15 minutes. Microsomes were subsequently collected by ultra-centrifugation at 100,000×g for 1 hour; membrane pellets were stored at −80° C. until further analyzed.

[0063] Antisera to p32 were generated by injecting rabbits with p32 (amino acid residues 19-318) expressed as a fusion protein with GST. The bacterial expression vector pGEX 2T was used and the GST-fusion protein was induced and purified, as recommended by the supplier (Pharmacia). Each rabbit received a subcutaneous injection of 75 ug of fusion protein emulsified in Freunds complete adjuvant. The rabbits were boostered with 50 ug of fusion protein emulsified in Freunds incomplete adjuvant every second week. Blood was collected every second week. The immune rabbit sera were passed over a column containing GST fusion-protein immobilized on CNBr activated Sepharose beads. Bound Ig was eluted with 0.1 M sodium citrate buffer (pH 3.0), containing 0.5 M NaCl. To remove Ig to the GST portion of the fusion protein, the eluted Ig was similarly incubated with GST-coupled Sepharose beads and the unbound Ig fraction was used. For immunoblot analysis of the over expressed protein, the Ig was used at a concentration of 1 ug per ml. The details of the immunoblotting procedure are described in detail in Bavik et al., J. Biol. Chem., 267:23035-23042 (1992) the disclosure of which is herein incorporated by reference.

[0064] As shown in FIG. 8A, the above procedure resulted in expression of p32 in cells transfected with the recombinant expression vector, but not in control cells that were mock transfected.

[0065] Next, the enzymatic properties of p32 expressed in COS-cells was assayed in a manner similar to that as described in the study of 11-cis-retinol dehydrogenase activity in microsomal fractions of RPE cells. See Saari et al., Anal. Biochem 213:28-13226 (1993).

[0066] In particular, the enzymatic activity of p32 was confirmed by incubating the microsomal fractions from the aforementioned transfected cells, and from control cells lacking p32, with varying combinations of the different stereo isomeric substrates, i.e., 11-cis-retinol or all-trans-retinol, in the presence of either cofactor NAD+ or NADP.

[0067] To prepare the substrate, 11-cis retinol was synthesized from 11-cis-retinaldehyde using sodium borohydride, as set fourth in Heller et al., J. Biol. Chem. 248:6308-6316 (1973), and stored under argon at 80° C. HPLC analysis confirmed the quantitative reduction of 11-cis-retinaldehyde to 11-cis-retinol, and all manipulations with the retinoids were done under subdued lighting conditions.

[0068] To assay for p32 activity in transfected cells, the final concentration of 11-cis-retinol and all-trans-retinol (obtained from Sigma Chemical Co.) in the incubations was reduced to 100 uM. Twenty ug of total membrane protein from COS-cells expressing p32 or from control cells were used in each incubation, and thereafter a 30 minute incubation at 37° C. in the presence or absence of NAD+ or NADP followed. Reaction mixtures were then extracted with n-hexane, and organic phases removed and dried under argon. The dried organic phases were then separately dissolved in ethanol and aliquots were analyzed on a normal phase silica HPLC column developed with n-hexane containing 4% dioxane at 1 ml per minute. See Saari et al. J. Biol. Chem. 257:13329-13333 (1982). Effluent was monitored at 330 nm. Under these conditions, 11-cis-retinaldehyde and 11-cis retinol eluted at 7 minutes and 22.5 minutes, respectively, and all-trans-retinaldehyde and all-trans retinol eluted at 8 minutes and 23 minutes, respectively.

[0069] As indicated in FIG. 8B, the aforementioned HPLC analysis shows that fractions from transfected cells containing p32 expressed 11-cis-retinol dehydrogenase protein which was active in the presence of NAD+, as indicated by the formation of 11-cis-retinaldehyde. A second peak in the chromatogram is all-trans retinaldehyde; however, control incubations with 11-cis retinaldehyde, in the absence of cellular membranes, show that, under the test procedure employed, a large amount of 11-cis retinaldehyde isomerizes to all-trans retinaldehyde. This indicates that the appearance of all-trans retinaldehyde is due to its generation during the incubation process used and extraction procedures, and is not an enzymatic reaction product. Further, incubations with all-trans retinol with cells containing p32 verify the stereo specificity of the enzyme, as no significant formation of all-trans retinaldehyde is detected.

[0070] As shown in FIG. 8C, p32 is not enzymatically active in the presence of cofactor NADP.

[0071] In FIG. 8D, assays of the control cells not expressing p32 show that these do not oxidize 11-cis-retinol into 11-cis-retinaldehyde.

[0072] Therefore, the above shows conclusively that p32 is a stereo specific 11-cis-retinol dehydrogenase, which relies on NAD+ as its cofactor.

EXAMPLE 11

[0073] Following the work described supra, using bovine materials, additional experiments were carried out to isolate and to clone a human sequence.

[0074] A cDNA library from human eye, in λgt11 was purchased from a commercial supplier (i.e., Clontech). The bovine cDNA described supra, i.e., SEQ ID NO: 10, was used as a probe. The cDNA was ³²[P]dCTP labelled by random priming to a high specific activity (about 10⁹ cpm/μg of DNA).

[0075] The labelled bovine cDNA was then used to probe the human cDNA library. Conditions were as follows: hybridization in 6×SSC, 0.5% SDS, 5×Denhardt's solution, 25% formamide, at 68° C., with 100 μg/ml of salmon sperm DNA, followed by four washes of 2×SSC, 0.5% SDS, at 65° C., for 30 minutes each, and then a final wash at 2×SSC at 42° C. for 30 minutes.

[0076] When a positive cDNA was found, the insert (i.e., the cDNA), was excised following the manufacturer's instructions, and then subcloned into the commercially available vector pBluescript. The sequence of the insert was then determined, using well known methods. The sequence of 1128 nucleotides is set forth at SEQ ID NO: 14. The corresponding amino acid sequence of 318 residues is se forth in SEQ ID NO:15.

EXAMPLE 12

[0077] In further experiments, the information described in example 11, supra, was used to study and to analyze bovine neuroretina and murine 10 day embryos. Murine embryos were used because, apart from the general usefulness of the system for studying developmental biology, retinol dehydrogenases are extremely active in development. The model is extrapolatable to human development.

[0078] RNA (5-10 μg), was isolated from bovine neuroretinas, or from murine 10 day embryos, using well known techniques. The RNA was mixed in 4μl of 5×AMVRT buffer, together with 4μl of dNTPs from 5 mM stock solutions, 2 μl of oligo dT (18mer, at a final concentration of 10 μM), together with 0.5 μl RNAse inhibitor, and 2μl of avian myelostosis virus reverse transcriptase (10U). The final volume was 20 μl. This resulting mixture was incubated at 42° C. for 30 minutes, and then left on ice until used.

[0079] PCR was then carried out. In the PCR, two μl of cDNA were used. Primers were designed on the basis of the deduced amino acid sequence for bovine cDNA set forth supra. The following conserved amino acid sequences were noted: A) Cys Asp Ser Gly Phe Gly B) Pro Gly Trp Asp Ala C) Glu Ala Phe Ser Asp D) His Pro Arg Thr

[0080] “A” corresponds to amino acids 36-41 of SEQ ID NO:12. “B” is found at amino acids 283-287 of this sequence. “C” is found at positions 183-187, and “D” at positions 276-279. “Conserved” as used herein refers to conservation between the deduced sequence, the sequence for liver RDH shown by Chai, et al. J. Biol. Chem 270: 3900-3904 (1995), incorporated by reference in its entirety, and Simon, et al, J. Biol. Chem 270: 1107-1112 (1995), also incorporated by reference.

[0081] Degenerate oligomers were prepared. In a first set of PCR experiments, degenerate oligos based upon A and B were used as primers, i.e.: 5′- A C G T G A A T T C T G Y G A Y T C N G G N W T Y G G - 3′ (SEQ ID NO:16) 5′- A C G T G A A T T C T T N G C R T C C C C A N C C - 3′ (SEQ ID NO:17)

[0082] as forward and reverse primers respectively. The primers were mixed with the two μl of cDNA discussed supra. Conditions were 1 minute of denaturation at 94° C., 1 minute of annealing at 50° C., and two minutes at 72° C., for elongation. This constituted 1 cycle. Twenty-five cycles were carried out.

[0083] Following the first PCR, 5 μl samples of PCR product were combined with primers based upon “C” and “D,” i.e.: 5′- A C G T G A A T T C G A R G C N T T Y T C N G A - 3′ (SEQ ID NO:18) 5′- A C G T G A A T T C C G N G T N C K N G G R T G - 3′ (SEQ ID NO:19)

[0084] as forward and reverse primers, respectively. Conditions were exactly as used in the first set of experiments, except that the annealing temperature was 55° C.

[0085] Reaction products were analyzed on 1.5% agarose gels with ethidium bromide. The assumption was that the amplification products should be about 300 base pairs in length. As such, any 300 base pair bands visualized confirmed that the PCR protocol generated products of appropriate size. The experiments were repeated, using 1% low melting point agarose gels, and the PCR products were eluted therefrom. The isolated products were reamplified, using the same protocols, and were cloned into plasmids (TA cloning kit, Invitrogen). The plasmid DNA was prepared from transformants using standard protocols, and then analyzed by restriction digestion, using EcoRI. Any inserts of about 300 base pairs were analyzed further, using vector specific primers. The PCR products are presented in SEQ ID NOS: 20-23 with deduced amino acid sequences being presented as SEQ ID NOS: 24-27. SEQ ID NOS: 20 and 24 correspond to bovine sequences, while all others are murine sequences. In these nucleotide sequences, the first base (“C”) is an artifact of the experiment, resulting from cleavage by a restriction endonuclease. Hence, one begins with the second nucleotide base in determining the deduced amino acid sequence. Further, note that sequences corresponding to the degenerate oligos, which would normally be included at the 5′ and 3′ termini, are not included.

EXAMPLE 13

[0086] The PCR product set forth in SEQ ID NO: 19 was then used in further probing experiments.

[0087] A murine 8.5 day cDNA library (in λgt10), was screened, using randomly labelled SEQ ID NO: 22, where the hydridization took place in 6×SSC, 0.5% SDS, 5×Denhardts's solution, 50% formamide at 42° C., with 100 μg/ml of salmon sperm DNA, followed by one wash at 2×SSC, 0.5% SDS at 50° C. for 30 minutes. A positive cDNA clone was identified, subcloned into pBluescript, and sequenced. The nucleotide sequence, and deduced amino acid sequence, are set forth as SEQ ID NOS: 28 and 29.

EXAMPLE 14

[0088] Following the work described, supra, the human cDNA was used to probe a human genomic library. The probe was prepared by PCR and randomly labelled as described supra.

[0089] The primers used in the PCR were derived from the cDNA sequence of SEQ ID NO:11 and were as follows: Forward primer: 5′- G C T T C G G G C G C T G T A G T A-3′ (SEQ ID NO:30) and Reverse Primer: 5′- A A A A C A A T C T C T T G C T G G A A-3″ (SEQ ID NO:31)

[0090] PCR was carried out by denaturing at 95° C., followed by annealing at 55° C., and elongation at 72° C. 2-5U of Taq polymerase and 0.2μM of each primer were used. Thirty cycles were carried out.

[0091] The amplified fragment of 1056 bp was isolated, following agarose gel electrophoresis analysis and cloned into vector PCR (commercially available from Invitrogen). This probe was used to screen a human genomic library in λFXII vector, from Stratagene. The manufacturer's instructions were followed to screen approximately 1×10⁶ plaque forming units. 10⁶ cpm/ml of hybridization solution was used. Hybridization was carried out overnight with 6×SSC, 0.5% SDS, 5×Denhardt's solution, 50% formamide at 42° C., with 100μg/ml of salmon sperm DNA, followed by one wash at 1×SSC, 0.1% SDS at 50° C. and a final wash at 0.5×SSC, 0.1% SDS at 65° C. Each wash was for 30 minutes. Several positive plaques were isolated, rescreened, and λDNA prepared, using the glycerol step gradient method described by Sambrook et al. Molecular Cloning, A Laboratory Manual (2d edition, 1989), incorporated by reference.

[0092] The isolated genomic clones were sequenced by analyzing fragments obtained following PCR reactions, using 100 mg of genomic λ clones per reaction as templates. To carry out the PCR, different primers, derived from the cDNA sequence of SEQ ID NO:1l were used in two PCR reactions, numbered ‘one’ and ‘two’.

[0093] Specifically, the primers used in PCR reaction one were SEQ ID NO:30, supra (forward primer) and 5′-C T C A G G C T G T C A G A G A A G G C C T-3′ (SEQ ID NO:32) (reverse primer)

[0094] The primers used in PCR reaction two were 5′-G A C G A T T T C C A G C G G G T G C-3′ (SEQ ID NO:33) (forward primer) and SEQ ID NO:31, supra

[0095] PCR was carried out by denaturing at 95° C., followed by annealing at 55° C. and elongation at 72° C. 2-5U of Taq polymerase and 0.2μM of each primer was used. Thirty cycles were carried out. The amplified fragments from reactions one and two, were 2.2 kb and 2.5 kb respectively. Each fragment was cloned into vector PCR commercially available from Invitrogen.

[0096] Sequence analysis of the cloned fragments using vector specific primers or internal primers, permitted identification of exon-intron boundaries.

[0097] The structure of the gene is presented in FIG. 9.

EXAMPLE 15

[0098] Studies were carried out to identify the location of the gene on chromosomes.

[0099] To do this, high molecular weight DNA was isolated from human leuckoytes, Chinese hamster cells, murine liver cells, and from hamster/human and mouse/human somatic hybrid cell lines. These hybrid cell lines each retained one human chromosome, as well as rodent genomes.

[0100] The isolated DNA was digested with Hind III, fractionated on agarose gel via electrophoresis, and then transferred to a nylon filter. These were then probed, using the human cDNA described supra, labelled as described supra.

[0101] Slides of chromosomes were prepared from lymphocyte cultures, using art recognized techniques. The λDNA from 3 genomic clones were mixed and labelled with biotinylated 16 dUTP, by Nick translation. A centromere specific probe for human chromosome 12 centromere (obtained from the ATCC, under Accession Number D12Z1), was labelled with fluoro-red-dUTP, following the manufacturer's instructions. Pre-annealing of the probes, pretreatment of the slides, hybridization conditions, signal amplification, and detection, were in accordance with well known techniques. Chromosomes were counter-stained with 4,6 diamino-2-phenyl indole (DAPI), and signal was visualized using a fluorescence microscope.

[0102] Analysis of all of these data indicated that the gene for human 11-cis RDH spans more than 4 kilobases, and is divided into 4 coding exons, which range from 165 to 342 base pairs in length. Further, an exon was found in the 5 untranslated region, and the length of the last coding exon has not been established. Introns range in size from 250 base pairs to 1.9 kilobases. FIG. 9 shows this schematically.

[0103] Study of exon/intron boundaries showed that all splice donor and acceptor sites follow the well known, canonical GT/AG rule. The Initiation codon and the conserved cofactor binding site are encoded by exon 2, while the active site, with invariant tyrosine residue, is encoded by exon 3. The gene for human 11-cis RDH maps to chromosome 12q13-14.

[0104] As shown above, this invention provides a method for the isolation and characterization of a novel protein, p32, which associates with the p63 of RPE. The primary structure of p32 demonstrates that it has all the critical features of a functional short-chain alcohol dehydrogenase including a putative cofactor binding site and essential residues involved in the catalytic mechanism, namely the almost invariant tyrosine containing sequence motif Y-X-X-X-K (Persson et al., Eur. J. Biochem. 200:537-543 (1991)). The restricted tissue expression and the abundance of p32 in RPE indicates that this protein carries out a function which is unique to the RPE. This possibility, and the fact that it forms a complex with p63 which previously has been shown to be a component of the retinoid uptake machinery in RPE-cells (Bavik, et al., J. Biol. Chem. 267:23035-23042 (1992)), shows that the substrate for p32 is a retinoid.

[0105] A major metabolic step in retinoid metabolism in RPE-cells is the conversion of 11-cis retinol to 11-cis retinaldehyde. Based on the results obtained hereinabove showing the restricted expression of p32 in the RPE, and the particular biochemical properties of this protein further investigation confirmed that p32 is in fact an 11-cis-retinol dehydrogenase, the enzyme which catalyzes this reaction.

[0106] One aspect of the invention is the ability to produce recombinant 11-cis-retinol dehydrogenase. The recombinant enzyme can be used to produce 11-cis-retinaldehyde in levels higher, and in purer form, than would be available using standard biochemical methodologies. Thus, the isolated nucleic acid molecules of the invention, which include SEQ ID NOS: 10, 14, 20-23, 28 and 29, as well as sequences which have complements which hybridize to the listed sequences, under stringent conditions as well as those nucleic acid molecules which hybridize to SEQ ID NO: 10 under stringent conditions can be used in this context. By the term “stringent conditions” is meant hybridization in 6×SSC, 0.5% SDS, 5×Denhardt's solution at 68° C., with 100 μg/ml of salmon sperm DNA, and a final wash with 0.5-1.0×SSC at 50° C. The term is also used herein to refer to any set of parameters which are at least as stringent as those set forth above. As is well known, equally stringent conditions can be created by changing one parameter to make it less stringent, with another parameter being changed to increase its stringency. Thus, any nucleic acid molecule which fulfills the hybridization criteria set forth herein will be expected to code for p32 or a p32 homologue. These nucleic acid molecules preferably encode mammalian retinol dehydrogenases, such as 11-cis-retinol dehydrogenase. Exemplary, but by no means the only mammalian species included, are human, bovine and murine enzymes. The enzyme may be produced in an in vitro system, such as the one described above, or via transfecting or transforming eukaryotic or prokaryotic cell lines, such as CHO and COS cells or bacterial strains such as E. coli or the yeast strain S.cervisiae with the nucleic acid molecules of the invention. In an especially preferred embodiment, the nucleic acid molecules are contained within an expression vector, operably linked to a promoter. Complementary DNA, or “cDNA” is preferred, but genomic DNA and mRNA can also be used.

[0107] The identification of the p32, 11-cis retinol dehydrogenase, as a member of the short-chain alcohol dehydrogenase superfamily is important in view of the retinoid-metabolism which occurs in non-ocular tissues. Studies show that generation of all-trans retinoic acid from all-trans retinol is carried out in a two step process (Posch et al., Biochemistry 30:6224-6230 (1991)). First, retinol is oxidized to retinal by a membrane bound retinol dehydrogenase. In a second step, the retinal is oxidized to retinoic acid. Thus, the oxidation of retinol into retinal, occurring in non-ocular tissues, is similar to the reaction carried out during synthesis of 11-cis retinal from 11-cis retinol in the visual cycle. In light of these similarities, it can be proposed that formation of all-trans retinal from all-trans retinol is carried out by an enzyme which is structurally similar to the p32 11-cis retinol dehydrogenase isolated by this invention. These findings are surprising in contrast to presently held views as it is generally believed that this metabolic step is carried out by members of the medium chain alcohol dehydrogenases. See Duester, Alcohol Clin. Exp. Res. 15:568-572 (1991); Yang et al., Alcohol Clin. Exp. Res. 17:496 (1993) and Zgombic-Knight et al., J. Biol. Chem. 269:6790-6795 (1994). Thus the identification and structural characterization of the p32 11-cis retinol dehydrogenase, provided by this invention also provides a previously unexpected avenue for the isolation and characterization of similar dehydrogenases involved in retinol metabolism is non-ocular tissues.

[0108] The p32 protein and nucleic acid encoding therefor and other aspects of this invention are also useful in many other important applications. For example, as it has been shown that p32 is part of an oligomeric protein complex which functions as a membrane receptor for RBP in RPE-cells, the nucleic acid sequence coding for p32 can be used in a phenotypic/genic diagnostic analysis to determine retinoid accumulation, which can lead to retinitis pigmentosa.

[0109] Additionally, as shown, p32 possesses 11-cis-retinol dehydrogenase activity, which catalyzes the conversion of 11-cis retinol to 11-cis-retinaldehyde, a major metabolic step in retinoid metabolism in RPE-cells carried out by a membrane bound dehydrogenase. Thus, retinoid accumulation may be directly or indirectly tied to the presence of p32 and/or its activation or inhibition, for example, its complex formation with the RBP receptor p63.

[0110] In other applications the effect of potential retinoid drugs for treatment of various diseases on the 11-cis-retinal dehydrogenase activity of p32 may be assayed as such drugs may adversely effect the enzyme, and to thus determine which of the different drugs have limited or no adverse effect on enzyme activity.

[0111] Examples of such diseases include those of the eye and also skin disorders such as psoriasis and acne. Certain cancers such as T-cell leukemias may also be tested by retinoid drugs and hence be candidates for assaying p32 activity.

[0112] The various known functions of retinoids also suggests that various other retinoid linked pathological conditions may be diagnosed via assays for levels of the p63/p32 receptor complex associated with a particular retinol binding protein. Art recognized techniques may be used, such a immunoassays, and so forth, to determine whether p63/p32 receptor complex levels are too low or too high—i.e., are at variance with a normal level.

[0113] Further, as p32 complexes with the p63 component of the retinoid uptake machinery in RPE cells, it may also be used in a therapeutic context, as it is well known that soluble receptors may be used to prevent binding of a protein to its membrane-linked receptor. Thus, a subject characterized by enhanced levels of production of retinol binding protein may be treated via administering an amount of soluble receptor complex or antibody sufficient to inhibit binding of the retinol binding protein or other related molecule to its target, namely, an inhibitor of p32's retinol dehydrogenase activity. Other aspects of the invention will be clear to the skilled artisan and need not be repeated here.

[0114] In yet another application, monoclonal and polyclonal antibodies to p32 can be generated, which are useful, inter alia, in monitoring the instance of pathological conditions characterized by aberrant levels of a receptor for retinol binding protein, by binding analysis of the antibody with body fluid or tissue samples. The generation of antibodies to p32 can be accomplished, for example, by using the procedure set out in Bavik et al., J. Biol. Chem. 268:20540-20546 (1993) for the generation of antibodies to p63, including mAb A52.

[0115] The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, it being recognized that various modifications are possible within the scope of the invention.

[0116] As shown above, this invention provides a method for the isolation and characterization of a novel protein, p32, which associates with the p63 of RPE. The primary structure of p32 demonstrates that it has all the critical features of a functional short-chain alcohol dehydrogenase including a putative cofactor binding site and essential residues involved in the catalytic mechanism, namely the almost invariant tyrosine containing sequence motif Y-X-X-X-K (Persson et al., Eur. J. Biochem. 200:537-543 (1991)). The restricted tissue expression and the abundance of p32 in RPE indicates that this protein carries out a function which is unique to the RPE. This possibility, and the fact that it forms a complex with p63 which previously has been shown to be a component of the retinoid uptake machinery in RPE-cells (Bavik, et al., J. Biol. Chem. 267:23035-23042 (1992)), shows that the substrate for p32 is a retinoid.

[0117] A major metabolic step in retinoid metabolism in RPE-cells is the conversion of 11-cis retinol to 11-cis retinaldehyde. Based on the results obtained hereinabove showing the restricted expression of p32 in the RPE, and the particular biochemical properties of this protein further investigation confirmed that p32 is in fact an 11-cis-retinol dehydrogenase, the enzyme which catalyzes this reaction.

1 41 18 amino acids amino acid linear protein 1 Leu Val Glu Ala Val Leu Ala Glu Val Leu Pro Lys Pro Ala Gln Thr 5 10 15 Val Ala 8 amino acids amino acid linear protein 2 Tyr Ser Pro Gly Trp Asp Ala Lys 5 15 amino acids amino acid linear protein 3 Thr Pro Val Thr Asn Leu Glu Thr Leu Glu Asp Thr Leu Gln Ala 5 10 15 7 amino acids amino acid linear protein 4 Asp Val Ala Pro Phe Gly Val 5 14 amino acids amino acid linear protein 5 Leu His Thr Thr Leu Leu Asp Val Thr Asp Pro Gln Ser Ile 5 10 23 base pairs nucleic acid single linear nucleic acid 6 ACGTGAATTC TNGTNGARGC NGT 23 27 base pairs nucleic acid single linear nucleic acid 7 ACGTGAATTC ACNGTYTGNG CNGGYTT 27 24 base pairs nucleic acid single linear nucleic acid 8 ACGTGAATTC CCNGTNACNA AYYT 24 27 base pairs nucleic acid single linear nucleic acid 9 ACGTGAATTC GCYTGNARNG TRTCYTC 27 1122 base pairs nucleic acid single linear cDNA p32;11-cis retinol dehydrogenase 10 AGCTTTCCCC TGAGGAGGTC ACCTGGGCTC CAGCC ATG TGG CTG CCT CTG CAG 53 Met Trp Leu Pro Leu Leu 5 TGC CTG CTG CTG GGT GTC TTG CTC TGG GCA GCA CTG TGG TTG CTC AGG 101 Leu Gly Val Leu Leu Trp Ala Ala Leu Trp Leu Leu Arg Asp Arg Gln 10 15 20 GAC CGG CCA GCC AGC GAT GCC TTT ATC TTC ATC ACC GGC TGT GAC TCG 149 Cys Leu Pro Ala Ser Asp Ala Phe Ile Phe Ile Thr Gly Cys Asp Ser 25 30 35 GGC TTT GGG CGG CTC CTT GCT CTG AGG CTG GAC CAG AGA GGC TTC CGA 197 Gly Phe Gly Arg Leu Leu Ala Leu Arg Leu Asp Gln Arg Gly Phe Arg 40 45 50 GTA CTG GCC AGC TGC CTG ACA CCC TCG GGG GCG GAG GAC CTC CAG CGG 245 Val Leu Ala Ser Cys Leu Thr Pro Ser Gly Ala Glu Asp Leu Gln Arg 55 60 65 70 GTC GCC TCC TCC CGC CTC CAC ACC ACC CTG CTG GAT GTC ACA GAT CCC 293 Val Ala Ser Ser Arg Leu His Thr Thr Leu Leu Asp Val Thr Asp Pro 75 80 85 CAG AGC ATC CGG CAG GCA GTC AAG TGG GTG GAA ACG CAT GTT GGG GAA 341 Gln Ser Ile Arg Gln Ala Val Lys Trp Val Glu Thr His Val Gly Glu 90 95 100 GCA GGG CTT TTT GGT CTG GTG AAT AAT GCT GGT GTG GCT GGC ATC ATT 389 Ala Gly Leu Phe Gly Leu Val Asn Asn Ala Gly Val Ala Gly Ile Ile 105 110 115 GGT CCC ACC CCA TGG CAG ACG CGG GAG GAC TTC CAG CGG GTG CTG AAT 437 Gly Pro Thr Pro Trp Gln Thr Arg Glu Asp Phe Gln Arg Val Leu Asn 120 125 130 GTG AAC ACG CTG GGT CCC ATC GGG GTC ACC CTC GCC CTG CTG CCC CTG 485 Val Asn Thr Leu Gly Pro Ile Gly Val Thr Leu Ala Leu Leu Pro Leu 135 140 145 150 CTG CTG CAG GCC CGG GGC CGA GTG ATC AAC ATC ACC AGT GTC CTT GGC 533 Leu Leu Gln Ala Arg Gly Arg Val Ile Asn Ile Thr Ser Val Leu Gly 155 160 165 CGT CTG GCA GCC AAT GGA GGG GGC TAC TGC GTC TCC AAG TTT GGC CTG 581 Arg Leu Ala Ala Asn Gly Gly Gly Tyr Cys Val Ser Lys Phe Gly Leu 170 175 180 GAG GCC TTC TCT GAC AGC CTG AGG CGA GAT GTG GCT CCT TTT GGG GTA 629 Glu Ala Phe Ser Asp Ser Leu Arg Arg Asp Val Ala Pro Phe Gly Val 185 190 195 CGG GTC TCT ATC GTG GAA CCT GGC TTC TTC CGA ACC CCT GTG ACA AAC 677 Arg Val Ser Ile Val Glu Pro Gly Phe Phe Arg Thr Pro Val Thr Asn 200 205 210 CTG GAA ACT TTG GAG GAC ACC CTG CAG GCC TGC TGG GCA CGG CTG CCT 725 Leu Glu Thr Leu Glu Asp Thr Leu Gln Ala Cys Trp Ala Arg Leu Pro 215 220 225 230 CCA GCC ACA CAG GCC CTC TAT GGG GAG GCC TTC CTC ACC AAA TAC CTG 773 Pro Ala Thr Gln Ala Leu Tyr Gly Glu Ala Phe Leu Thr Lys Tyr Leu 235 240 245 AGA GTG CAG CAA CGT ATC ATG AAC ATG ATC TGT GAT CCG GAC CTG GCC 821 Arg Val Gln Gln Arg Ile Met Asn Met Ile Cys Asp Pro Asp Leu Ala 250 255 260 AAG GTG AGC AGG TGC CTG GAG CAT GCC CTA ACT GCC CGT CAC CCC AGA 869 Lys Val Ser Arg Cys Leu Glu His Ala Leu Thr Ala Arg His Pro Arg 265 270 275 ACC CGC TAC AGC CCA GGC TGG GAT GCC AAG CTG CTC TGG TTG CCA GCC 917 Thr Arg Tyr Ser Pro Gly Trp Asp Ala Lys Leu Leu Trp Leu Pro Ala 280 285 290 TCC TAC TTG CCA GCC AGG CTG GTG GAT GCT GTG CTC GCC TGG GTC CTT 965 Ser Tyr Leu Pro Ala Arg Leu Val Asp Ala Val Leu Ala Trp Val Leu 295 300 305 310 CCC AAG CCT GCC CAG ACA GTC TAC TAA ATCCAGCCCT CCAGCAAAAG 1012 Pro Lys Pro Ala Gln Thr Val Tyr 315 ATGGTTGTTC AAGGCAAGGA CTCTGATTTA TTCTGTCCCC TACCCTGGTA CTGCCTGG 1072 TGTGGCATAA AACAGTCACT CAATAAATGT ATTATTCAAA ACAAAAAAAA 1122 344 amino acids amino acid linear protein Rat D-b-hydroxybutyrate dehydrogenase (rBDH) 11 Met Met Leu Ala Ala Arg Leu Ser Arg Pro Leu Ser Gln Leu Pro Gly 5 10 15 Lys Ala Leu Ser Val Cys Asp Arg Glu Asn Gly Thr Arg His Thr Leu 20 25 30 Leu Phe Tyr Pro Ala Ser Phe Ser Pro Asp Thr Arg Arg Thr Tyr Thr 35 40 45 Ser Gln Ala Asp Ala Ala Ser Gly Lys Ala Val Leu Val Thr Gly Cys 50 55 60 Asp Ser Gly Phe Gly Phe Ser Leu Ala Lys His Leu His Ser Lys Gly 65 70 75 80 Phe Leu Val Phe Ala Gly Cys Leu Leu Lys Glu Gln Gly Asp Ala Gly 85 90 95 Val Arg Glu Leu Asp Ser Leu Lys Ser Asp Arg Leu Arg Thr Ile Gln 100 105 110 Leu Asn Val Cys Asn Ser Glu Glu Val Glu Lys Ala Val Glu Thr Val 115 120 125 Arg Ser Gly Leu Lys Asp Pro Glu Lys Gly Met Trp Gly Leu Val Asn 130 135 140 Asn Ala Gly Ile Ser Thr Phe Gly Glu Val Glu Phe Thr Ser Met Glu 145 150 155 160 Thr Tyr Lys Glu Val Ala Glu Val Asn Leu Trp Gly Thr Val Arg Thr 165 170 175 Thr Lys Ser Phe Leu Pro Leu Leu Arg Arg Ala Lys Gly Arg Val Val 180 185 190 Asn Ile Ser Ser Met Leu Gly Arg Met Ala Asn Pro Ala Arg Ser Pro 195 200 205 Tyr Cys Ile Thr Lys Phe Gly Val Glu Ala Phe Ser Asp Cys Leu Arg 210 215 220 Tyr Glu Met His Pro Leu Gly Val Lys Val Ser Val Val Glu Pro Gly 225 230 235 240 Asn Phe Ile Ala Ala Thr Ser Leu Tyr Ser Pro Glu Arg Ile Gln Ala 245 250 255 Ile Ala Lys Lys Met Trp Asp Glu Leu Pro Glu Val Val Arg Lys Asp 260 265 270 Tyr Gly Lys Lys Tyr Phe Asp Glu Lys Ile Ala Lys Met Glu Thr Tyr 275 280 285 Cys Asn Ser Gly Ser Thr Asp Thr Ser Ser Val Ile Asn Ala Val Thr 290 295 300 His Ala Leu Thr Ala Ala Thr Pro Tyr Thr Arg Tyr His Pro Met Asp 305 310 315 320 Tyr Tyr Trp Trp Leu Arg Met Gln Val Met Thr His Phe Pro Gly Ala 325 330 335 Ile Ser Asp Lys Ile Tyr Ile His 340 327 amino acids amino acid linear protein Human estradiol 17-b dehydrogenase (hEDH) 12 Ala Arg Thr Val Val Leu Ile Thr Gly Cys Ser Ser Gly Ile Gly Leu 5 10 15 His Leu Ala Val Arg Leu Ala Ser Asp Pro Ser Gln Ser Phe Lys Val 20 25 30 Tyr Ala Thr Leu Arg Asp Leu Lys Thr Gln Gly Arg Leu Trp Glu Ala 35 40 45 Ala Arg Ala Leu Ala Cys Pro Pro Gly Ser Leu Glu Thr Leu Gln Leu 50 55 60 Asp Val Arg Asp Ser Lys Ser Val Ala Ala Ala Arg Glu Arg Val Thr 65 70 75 80 Glu Gly Arg Val Asp Val Leu Val Cys Asn Ala Gly Leu Gly Leu Leu 85 90 95 Gly Pro Leu Glu Ala Leu Gly Glu Asp Ala Val Ala Ser Val Leu Asp 100 105 110 Val Asn Val Val Gly Thr Val Arg Met Leu Gln Ala Phe Leu Pro Asp 115 120 125 Met Lys Arg Arg Gly Ser Gly Arg Val Leu Val Thr Gly Ser Val Gly 130 135 140 Gly Leu Met Gly Leu Pro Phe Asn Asp Val Tyr Cys Ala Ser Lys Phe 145 150 155 160 Ala Leu Glu Gly Leu Cys Glu Ser Leu Ala Val Leu Leu Leu Pro Phe 165 170 175 Gly Val His Leu Ser Leu Ile Glu Cys Gly Pro Val His Thr Ala Phe 180 185 190 Met Glu Lys Val Leu Gly Ser Pro Glu Glu Val Leu Asp Arg Thr Asp 195 200 205 Ile His Thr Phe His Arg Phe Tyr Gln Tyr Leu Ala His Ser Lys Gln 210 215 220 Val Phe Arg Glu Ala Ala Gln Asn Pro Glu Glu Val Ala Glu Val Phe 225 230 235 240 Leu Thr Ala Leu Arg Ala Pro Lys Pro Thr Leu Arg Tyr Phe Thr Thr 245 250 255 Glu Arg Phe Leu Pro Leu Leu Arg Met Arg Leu Asp Asp Pro Ser Gly 260 265 270 Ser Asn Tyr Val Thr Ala Met His Arg Glu Val Phe Gly Asp Val Pro 275 280 285 Ala Lys Ala Glu Ala Gly Ala Glu Ala Gly Gly Gly Ala Gly Pro Gly 290 295 300 Ala Glu Asp Glu Ala Gly Arg Ser Ala Val Gly Asp Pro Glu Leu Gly 305 310 315 320 Asp Pro Pro Ala Ala Pro Gln 325 244 amino acids amino acid linear protein E.coli 3-oxoacyl[acyl carrier protein]reductase (FABG) 13 Met Asn Phe Glu Gly Lys Ile Ala Leu Val Thr Gly Ala Ser Arg Gly 5 10 15 Ile Gly Arg Ala Ile Ala Glu Thr Leu Ala Ala Arg Gly Gly Lys Val 20 25 30 Ile Gly Thr Ala Thr Ser Glu Asn Gly Ala Gln Ala Ile Ser Asp Tyr 35 40 45 Leu Gly Ala Asn Gly Lys Gly Leu Met Leu Asn Val Thr Asp Pro Ala 50 55 60 Ser Ile Glu Ser Val Leu Glu Lys Ile Arg Ala Glu Phe Gly Glu Val 65 70 75 80 Asp Ile Leu Val Asn Asn Ala Gly Ile Thr Arg Asp Asn Leu Leu Met 85 90 95 Arg Met Lys Asp Glu Glu Trp Asn Asp Ile Ile Glu Thr Asn Leu Ser 100 105 110 Ser Val Phe Arg Leu Ser Lys Ala Val Met Arg Ala Met Met Lys Lys 115 120 125 Arg His Gly Arg Ile Ile Thr Ile Gly Ser Val Val Gly Thr Met Gly 130 135 140 Asn Gly Gly Gln Ala Asn Tyr Ala Ala Ala Lys Ala Gly Leu Ile Gly 145 150 155 160 Phe Ser Lys Ser Leu Ala Arg Glu Val Ala Ser Arg Gly Ile Thr Val 165 170 175 Asn Val Val Ala Pro Gly Phe Ile Glu Thr Asp Met Thr Arg Ala Leu 180 185 190 Ser Asp Asp Gln Arg Ala Gly Ile Leu Ala Gln Val Pro Ala Gly Arg 195 200 205 Leu Gly Gly Ala Gln Glu Ile Ala Asn Ala Val Ala Phe Leu Ala Ser 210 215 220 Asp Glu Ala Ala Tyr Ile Thr Gly Glu Thr Leu His Val Asn Gly Gly 225 230 235 240 Met Tyr Met Val 1128 base pairs nucleic acid double linear nucleic acid human 11-cis retinol dehydrogenase 14 TAAGCTTCGG GCGCTGTAGT ACCTGCCAGC TTTCGCCACA GGAGGCTGCC ACCTGTAGGT 60 CACTTGGGCT CCAGCTATGT GGCTGCCTCT TCTGCTGGGT GCCTTACTCT GGGCAGTGC 120 GTGGTTGCTC AGGGACCGGC AGAGCCTGCC CGCCAGCAAT GCCTTTGTCT TCATCACCG 180 CTGTGACTCA GGCTTTGGGC GCCTTCTGGC ACTGCAGCTG GACCAGAGAG GCTTCCGAG 240 CCTGGCCAGC TGCCTGACCC CCTCCGGGGC CGAGGACCTG CAGCGGGTGG CCTCCTCCC 300 CCTCCACACC ACCCTGTTGG ATATCACTGA TCCCCAGAGC GTCCAGCAGG CAGCCAAGT 360 GGTGGAGATG CACGTTAAGG AAGCAGGGCT TTTTGGTCTG GTGAATAATG CTGGTGTGG 420 TGGTATCATC GGACCCACAC CATGGCTGAC CCGGGACGAT TTCCAGCGGG TGCTGAATG 480 GAACACAATG GGTCCCATCG GGGTCACCCT TGCCCTGCTG CCTCTGCTGC AGCAAGCCC 540 GGGCCGGGTG ATCAACATCA CCAGCGTCCT GGGTCGCCTG GCAGCCAATG GTGGGGGCT 600 CTGTGTCTCC AAATTTGGCC TGGAGGCCTT CTCTGACAGC CTGAGGCGGG ATGTAGCTC 660 TTTTGGGATA CGAGTCTCCA TCGTGGAGCC TGGCTTCTTC CGAACCCCTG TGACCAACC 720 GGAGAGTCTG GAGAAAACCC TGCAGGCCTG CTGGGCACGG CTGCCTCCTG CCACACAGG 780 CCACTATGGG GGGGCCTTCC TCACCAAGTA CCTGAAAATG CAACAGCGCA TCATGAACC 840 GATCTGTGAC CCGGACCTAA CCAAGGTGAG CCGATGCCTG GAGCATGCCC TGACTGCTC 900 ACACCCCCGA ACCCGCTACA GCCCAGGTTG GGATGCCAAG CTGCTCTGGC TGCCTGCCT 960 CTACCTGCCA GCCAGCCTGG TGGATGCTGT GCTCACCTGG GTCCTTCCCA AGCCTGCC 1020 AGCAGTCTAC TGAATCCAGC CTTCCAGCAA GAGATTGTTT TTCAAGGACA AGGACTTT 1080 TTTATTTCTG CCCCCACCCT GGTACTGCCT GGTGCCTGCC ACAAAATA 1128 318 amino acids amino acid linear protein human 11-cis retinol dehydrogenase 15 Met Trp Leu Pro Leu Leu Leu Gly Ala Leu Leu Trp Ala Val Leu Trp 5 10 15 Leu Leu Arg Asp Arg Gln Ser Leu Pro Ala Ser Asn Ala Phe Val Phe 20 25 30 Ile Thr Gly Cys Asp Ser Gly Phe Gly Arg Leu Leu Ala Leu Gln Leu 35 40 45 Asp Gln Arg Gly Phe Arg Val Leu Ala Ser Cys Leu Thr Pro Ser Gly 50 55 60 Ala Glu Asp Leu Gln Arg Val Ala Ser Ser Arg Leu His Thr Thr Leu 65 70 75 80 Leu Asp Ile Thr Asp Pro Gln Ser Val Gln Gln Ala Ala Lys Trp Val 85 90 95 Glu Met His Val Lys Glu Ala Gly Leu Phe Gly Leu Val Asn Asn Ala 100 105 110 Gly Val Ala Gly Ile Ile Gly Pro Thr Pro Trp Leu Thr Arg Asp Asp 115 120 125 Phe Gln Arg Val Leu Asn Val Asn Thr Met Gly Pro Ile Gly Val Thr 130 135 140 Leu Ala Leu Leu Pro Leu Leu Gln Gln Ala Arg Gly Arg Val Ile Asn 145 150 155 160 Ile Thr Ser Val Leu Gly Arg Leu Ala Ala Asn Gly Gly Gly Tyr Cys 165 170 175 Val Ser Lys Phe Gly Leu Glu Ala Phe Ser Asp Ser Leu Arg Arg Asp 180 185 190 Val Ala His Phe Gly Ile Arg Val Ser Ile Val Glu Pro Gly Phe Phe 195 200 205 Arg Thr Pro Val Thr Asn Leu Glu Ser Leu Glu Lys Thr Leu Gln Ala 210 215 220 Cys Trp Ala Arg Leu Pro Pro Ala Thr Gln Ala His Tyr Gly Gly Ala 225 230 235 240 Phe Leu Thr Lys Tyr Leu Lys Met Gln Gln Arg Ile Met Asn Leu Ile 245 250 255 Cys Asp Pro Asp Leu Thr Lys Val Ser Arg Cys Leu Glu His Ala Leu 260 265 270 Thr Ala Arg His Pro Arg Thr Arg Tyr Ser Pro Gly Trp Asp Ala Lys 275 280 285 Leu Leu Trp Leu Pro Ala Ser Tyr Leu Pro Ala Ser Leu Val Asp Ala 290 295 300 Val Leu Thr Trp Val Leu Pro Lys Pro Ala Gln Ala Val Tyr 305 310 315 27 base pairs nucleic acid single linear nucleic acid PCR primer 16 ACGTGAATTC TGYGAYTCNG GNWTYGG 27 25 base pairs nucleic acid single linear nucleic acid PCR primer 17 ACGTGAATTC TTNGCRTCCC CANCC 25 24 base pairs nucleic acid single linear nucleic acid PCR primer 18 ACGTGAATTC GARGCNTTYT CNGA 24 24 base pairs nucleic acid single linear nucleic acid PCR primer 19 ACGTGAATTC CGNGTNCKNG GRTG 24 262 base pairs nucleic acid double linear nucleic acid PCR clone 194 20 CTCTCTCAGA AGGGAGCTCT CCTACTTCGG AGTGAAGGTG GCTATGATTG AGCCTGGTTA 60 CTTTGTTACC AATATGACCC AAGATGAGGG TTTTATTGGA TACCTCCAGG CATTGTGGA 120 CCGGGCCAGC CCAGAGCTGA AAGAACTCTA TGGAGAAAAC TTCCCTGCTG ACTTCTTGA 180 GACATTGAGT TTACTGAAAC CACGGTGGAC TCAGAATCTG TCCTTGGTGA CCGACTGCA 240 GGAGCACGCC CTGACTGCCT GC 262 262 base pairs nucleic acid double linear nucleic acid PCR clone 207 21 CTCCCTCAGG AGGGGGCTCT CCTACTTTGG GGTGAAGGTG GCTATTATAG AGCCTGGCTT 60 CTTCCTGACC GGTGTGACCA GTAGTGCCAG ATTATGCTCA AATACCCAGA TGCTGTGGG 120 CCAGACCAGC TCAGAAATCA GGGAGATCTA TGGCGAGAAG TACCTGGCAT CCTATCTGA 180 AAGGCTAAAC GAATTGGACA AGAGGTGCAA CAAGGACCTG TCTTTGGTGA CTGACTGCA 240 GGAGCATGCT CTGACTGCCT GC 262 265 base pairs nucleic acid double linear nucleic acid PCR clone 200 22 CAGCCTGAGG CGGGACATGG CTCCGTTCGG AGTACAAGTC TCCATTGTGG AGCCTGGCT 60 CTTTCGAACC CCTGTGACCA ACCTGGAGAG TCTGGAGAGC ACCCTGAAGG CTTGTTGGG 120 CCGGCTACCT CCAGCTATAC AGGCCCACTA CGGGGAGGCC TTCCTCGATA CTCATCTTC 180 AGTACAGCGC CGCATCATGA ACCTGATCTG TGACCCAGAA CTAACGAAGG TGACCAGCT 240 CCTGGAGCAT GCCCTGACTG CTCGC 265 265 base pairs nucleic acid double linear nucleic acid PCR clone 215 23 CAGCCTGAGG CGAGATGTGG CTCCTTTTGG GGTACGGGTC TCTATCGTGG AACCTGGCTT 60 CTTCCGAACC CCTGTGACAA ACCTGGAAAC TTTGGAGGGC ACCCTGCAGG CCTGCTGGG 120 ACGGCTGCCT CCAGCCACAC AGGCCCTCTA TGGGGAGGCC TTCCTCACCA AATACCTGA 180 AGTGCAGCAA CGTATCATGA ACATGATCTG TGATCCGGAC CTGGCCAAGG TGAGCAGGT 240 CCTGGAGCAT GCCCTAACTG CCCGT 265 87 amino acids amino acid linear protein PCR clone 194 24 Ser Leu Arg Arg Glu Leu Ser Tyr Phe Gly Val Lys Val Ala Met Ile 5 10 15 Glu Pro Gly Tyr Phe Val Thr Asn Met Thr Gln Asp Glu Gly Phe Ile 20 25 30 Gly Tyr Leu Gln Ala Leu Trp Asn Arg Ala Ser Pro Glu Leu Lys Glu 35 40 45 Leu Tyr Gly Glu Asn Phe Pro Ala Asp Phe Leu Lys Thr Leu Ser Leu 50 55 60 Leu Lys Pro Arg Trp Thr Gln Asn Leu Ser Leu Val Thr Asp Cys Met 65 70 75 80 Glu His Ala Leu Thr Ala Cys 85 87 amino acids amino acid linear protein PCR clone 207 25 Ser Leu Arg Arg Gly Leu Ser Tyr Phe Gly Val Lys Val Ala Ile Ile 5 10 15 Glu Pro Gly Phe Phe Leu Thr Gly Val Thr Ser Ser Ala Arg Leu Cys 20 25 30 Ser Asn Thr Gln Met Leu Trp Asp Gln Thr Ser Ser Glu Ile Arg Glu 35 40 45 Ile Tyr Gly Glu Lys Tyr Leu Ala Ser Tyr Leu Lys Arg Leu Asn Glu 50 55 60 Leu Asp Lys Arg Cys Asn Lys Asp Leu Ser Leu Val Thr Asp Cys Met 65 70 75 80 Glu His Ala Leu Thr Ala Cys 85 88 amino acids amino acid linear protein PCR clone 200 26 Ser Leu Arg Arg Asp Met Ala Pro Phe Gly Val Gln Val Ser Ile Val 5 10 15 Glu Pro Gly Phe Phe Arg Thr Pro Val Thr Asn Leu Glu Ser Leu Glu 20 25 30 Ser Thr Leu Lys Ala Cys Trp Ala Arg Leu Pro Pro Ala Ile Gln Ala 35 40 45 His Tyr Gly Glu Ala Phe Leu Asp Thr His Leu Arg Val Gln Arg Arg 50 55 60 Ile Met Asn Leu Ile Cys Asp Pro Glu Leu Thr Lys Val Thr Ser Cys 65 70 75 80 Leu Glu His Ala Leu Thr Ala Arg 85 88 amino acids amino acid linear protein PCR clone 215 27 Ser Leu Arg Arg Asp Val Ala Pro Phe Gly Val Arg Val Ser Ile Val 5 10 15 Glu Pro Gly Phe Phe Arg Thr Pro Val Thr Asn Leu Glu Thr Leu Glu 20 25 30 Gly Thr Leu Gln Ala Cys Trp Ala Arg Leu Pro Pro Ala Thr Gln Ala 35 40 45 Leu Tyr Gly Glu Ala Phe Leu Thr Lys Tyr Leu Arg Val Gln Gln Arg 50 55 60 Ile Met Asn Met Ile Cys Asp Pro Asp Leu Ala Lys Val Ser Arg Cys 65 70 75 80 Leu Glu His Ala Leu Thr Ala Arg 85 563 base pairs nucleic acid double linear nucleic acid clone ME207. 28 GAGGCGTTCT CGGACTCCCT CAGGAGGGGG CTCTCCTACT TTGGGGTGAA GGTGGCTATT 60 ATAGAGCCTG GCTTCTTCCT GACCGGTGTG ACCAGTAGTG CCAGATTATG CTCAAATAC 120 CAGATGCTGT GGGACCAGAC CAGCTCAGAA ATCAGGGAGA TCTATGGCGA GAAGTACCT 180 GCATCCTATC TGAAAAGGCT AAACGAATTG GACAAGAGGT GCAACAAGGA CCTGTCTTT 240 GTGACTGACT GCATGGAGCA TGCTCTGACT GCCTGCCACC CTCGCACGCG ATACTCAGC 300 GGCTGGGATG CTAAGCTCTT CTACCTCCCC TTGAGCTACC TGCCTACCTT TCTTGTGGA 360 GCCCTTCTCT ATTGGACTTC CCTGAAGCCT GAGAAAGCCC TCTGACGTGT TCACCTATG 420 GCATACCTGG GGAGATGTAG GTAGAGTTTG AGAGAGAGAA TATTTAGGGG AAATTTGGA 480 GGTTGAGGGA GGGAGTTTAT TACTCTGGGG TTCAGTCAAC ACACTTCATC TCATTAATT 540 TCCTATGACA CTACTGAATA CTG 563 134 amino acids amino acid linear protein clone ME207 29 Glu Ala Phe Ser Asp Ser Leu Arg Arg Gly Leu Ser Tyr Phe Gly Val 5 10 15 Lys Val Ala Ile Ile Glu Pro Gly Phe Phe Leu Thr Gly Val Thr Ser 20 25 30 Ser Ala Arg Leu Cys Ser Asn Thr Gln Met Leu Trp Asp Gln Thr Ser 35 40 45 Ser Glu Ile Arg Glu Ile Tyr Gly Glu Lys Tyr Leu Ala Ser Tyr Leu 50 55 60 Lys Arg Leu Asn Glu Leu Asp Lys Arg Cys Asn Lys Asp Leu Ser Leu 65 70 75 80 Val Thr Asp Cys Met Glu His Ala Leu Thr Ala Cys His Pro Arg Thr 85 90 95 Arg Tyr Ser Ala Gly Trp Asp Ala Lys Leu Phe Tyr Leu Pro Leu Ser 100 105 110 Tyr Leu Pro Thr Phe Leu Val Asp Ala Leu Leu Tyr Trp Thr Ser Leu 115 120 125 Lys Pro Glu Lys Ala Leu 130 18 base pairs nucleic acid single linear nucleic acid forward primer 30 GCTTCGGGCG CTGTAGTA 18 20 base pairs nucleic acid single linear nucleic acid Reverse primer 31 AAAACAATCT CTTGCTGGAA 20 1613 base pairs nucleic acid double linear 32 CATCCATACT GGTCAGAGGA ACATGATAGA AACCTGACAT TCTCAGTGCC TATACCTTCC 60 TGTGTAAGCA GCGGCCAGGC TCATTTTGAC ACAGAATATC TCTCTCTGCT TGACTTCTA 120 AAACCATGTG GCTCTACCTG GTTGCACTGG TGGGCCTGTG GACGCTCCTG CGCTTCTTC 180 GGGAGAGGCA GGTNGTGAGC CATCTCCAAG ACAAGTATGT CTTCATCACG GGCTGTGAC 240 CTGGCTTTGG GAACCTTCTG GCCAGACAAC TGGACAGGAG AGGCATGAGG GTGCTAGCT 300 CATGTCTGAC GGAGAAGGGA GCTGAGCAGC TGAGGAACAA GACATCTGAC AGGCTGGAG 360 CAGTGATCCT GGATGTCACC AAGACAGAGA GTATTGTGGC AGCCACTCAG TGGGTGAAG 420 AGCGTGTTGG GAACAGAGGA CTCTGGGGCC TGGTCAACAA TGCTGGCATC TGTGTCTTT 480 CTATCAATGA GTGGCTGAAA AAAGAGGACT TTGCAAATAT ACTGGATGTG AACCTGTTG 540 GCATGATCGA GGTGACTCTG AGCATGCTGC CCTTAGTGAG GAAGGCGAGG GGCCGTGTG 600 TCAACATCTC CAGCTCCATG GGTCGAGTGT CTTTGTGTGG TGGTGGTTAC TGCATCTCC 660 AGTATGGTGT AGAGGCCTTC TCAGACTCCC TCAGGAGGGA GATCTCCTAT TTTGGGGTG 720 AGGTGGCTAT CATAGAGCCT GGCGGGTTCA GGACTAATGT CTCCAACTAC GAGAGGCTA 780 CACACAGCAT AGAGAAGCTG TGGGACCAGA CATCCTCGGA GGTCAAGGAG GTCTATGAC 840 AGAATTTTCT GGACTCCTAT ATCAAAGCAA TACAGTCATT GACAGACACA TGCTCAGAT 900 ACCTGTCTGT GGTAACTGAC TGCATGGAGC ACGCTCTGAC TGCCTGTCAC CCTCGCACA 960 GATACTCAGC TGGCTGGGAT GCCAAGCTCT TCTACCTACC CTTGAGCTAC ATGCCCAC 1020 TCCTGGTAGA TGCCATGTTG TACTGGAGCT CTGTAAAGCC TGCCCAAGCC CTGTGAAT 1080 GCACGTGTGT GCAGACTTGT GGCGGGTGGA GGGAGATAAT GGCACAGGGC ATGTGGTT 1140 TGAGACTCAT TAAAACAATT CAGCTTCCAT ACTACTCAGA ACCAGTAAAG TTCAGGGG 1200 AGAGGCAGTA AAGTTCTGCC AAGGGGGAGT GATACAAAGG GGCTGGCAAT ATCCTGTG 1260 CTTAGCTTCT TGGGGCTTCA TCTTGGCCTA TTGTGAGAAT CCACAGGACT GCAGAGAT 1320 TAAACACCTA GGATGAGCTT TGCCTCTNNC CTTCCTCATG ATGTCCATGG GCCTGGCC 1380 CATGGAAGAT CGAAAGAATC CACTTCACAA TCACCTTTTT CCATGGTGTC AGGAGGGA 1440 GCCCCCACCC GCACTCCACA TCCTAATCGG CTTTAGGAGG TGGTTTTGCT GGTGGGAT 1500 AATCTTGCTA AGATAAACAA CAACAACAAT TTTTATTTGT CTCAAAACCA TGGTTTTT 1560 TTGGATTCCT TTCATTTCAG AATAAAAGTT GAAAAGATAA AAAAAAAAAA AAA 1613 1384 base pairs nucleic acid double linear 33 CTTTTTTTTT TTTTTTTTTG ACACAGAGTA TCTCTCTCTC TGCTTGACTT CTACAAGCCA 60 TGTGGCTCTA CCTGGTGGCA CTGGTGGGCC TGTGGACGCT TCTGCGCTTC TTCAGGGTG 120 GGCAGGTGGT GAGCCATCTC CAAGACAAAT ATGTCTTCAT CACGGGCTGT GACTCTGGC 180 TTGGGACCCT GCTGGCCAGA CAGCTGGACA GGAGAGGCAT GAGGGTGCTG GCTGCATGT 240 TGACGGAGAA GGGAGCCGAG GAGCTGAGGA ACAAGACATC TGACAGGCTG GAGACAGTG 300 TCCTGGATGT CACCAAGACA GAGAGTATTG TGACAGCCAC TCAGTGGGTG AAGGAGCAT 360 TTGGGAACAG AGGACTCTGG GGCCTGGTCA ACAACGCTGG CATCTCCACC CCCTCGGGT 420 CCAACGAGTG GATGAAAAAG CAGGACTTTG CACATGTACT GGATGTGAAC CTGTTGGGC 480 TGATCGAGGT GACTCTGAGC ATGCTGCCTT TAGTGAGGAA GGCGAGGGGT CGTGTGGTC 540 ACGTCTCCAG TGTCATGGGT CGAGTGTCTC TCTTTGGTGG TGGTTACTGC ATCTCTAAG 600 ATGGTGTAGA GGCCTTCTCA GACTCCCTCA GGAGGGAGCT CCGCTACTTT GGGGTGAAG 660 TGGCTATTAT AGAGCCTGGC TTCTTCCTGA CCGGTGTGAC CAGTAGTGCC AGATTATGC 720 CAAATACCCA GATGCTGTGG GACCAGACCA GCTCAGAAAT CAGGGAGATC TATGGCGAG 780 AGTACCTGGC ATCCTATCTG AAAAGGCTAA ACAAATTGGA CAAGAGGTGC AACAAGGAC 840 TGTCTGGGGT GACTGACTGC ATGGAGCATG CTCTGACTGC CTGTCACCCT CGTACCCGA 900 ACTCAGCTGG CTGGGATGCT AAGCTCTTCT ACCTCCCCTT GAGCTACCTG CCCACCTTT 960 TTGTGGATGC CCTTCTCTAC TGGACTTCCC TGAGGCCTGA AAAAGCCCTC TGAAAGTA 1020 CACCTATGTG CATACCTGGG GAGATGTAGG TAGAGTTTGA GAGAGAGAAT ATTTAGGG 1080 AATTAGGAGA GTTGGGGGGG GATTTTATTA CTCTGGGGTT CAGTCAATAC ACTTCATC 1140 GTTAATTCTC CTATGACACT ACTCAAGACT GATGATGACC AAAGAAATAG GCAAAGAA 1200 CTGCCAAGGG ATTCAGTTAC AAAAGAGCTG GCTGATGCCC AGATTATGAG CATCATGG 1260 ACCATGAAGG TCCACACAGA TGAGGAGGCT GGGACAAGTT TGTGCCAAAG CACTCTCC 1320 TGGTCCTCCT CTGCAGGAAA TGTACATGCC CTGGCTAGTT TAAACCCCTA TGCAAGAT 1380 AATT 1384 1240 base pairs nucleic acid double linear 34 CTTCTCTCTC TCTCTCTCTC TCTCTCCTCT TCTACAAACC ATGTGGCTCT ACATGGTGGC 60 GCTACTGGGC CTGTGGATGC TCCTGCGCTT TTTTAGAGAG AGGCAAGTGG TGGACCATC 120 TCAAGACAAG TATGTCTTCA TCACAGGCTG TGGCTCTGGC TTTGGGAACC TGCTGGCCA 180 ACAGCTGGAC AGGAGAGGCA TGAGAGTGTT GGCTGCATGT CGGAAGGAGG AGGGAGCCG 240 GGAGCTGAGG AGAAAGACAT CAGAAAGGCT GGAGACAGTG ATCCTGGATG TCACCAAGA 300 AGAGAATATT GTGGCAGCCA CTCAGTGGGT GAAGGAGCGT GTTGGGAACA GAGGACTCT 360 GGGCCTGGTC AACAACGCTG GCATCTCCGT CCCCTCGGGT CCCAACGAGT GGATGAAAA 420 ACAGGACTTT GCAAGTGTAC TGGATGTGAA CCTGTTGGGC TTGATCGAGG TGACTCTGA 480 CATGCTGCCC TTAGTGAGGA AGGCGAGGGG CCGTGTGGTC AACGTCTCCA GCATCTTGG 540 CAGAGTGTCA CTTGGTGGTA GTGGTGGTTA CTGCATCTCC AAGTATGGTA TAGAGGCCT 600 CTCAGACTCC CTTAGGAGGG ACGTCCGCTA CTTTGGGGTG AAGGTGGCTA TTATAGAGC 660 TGGCTTCTTC CTGACTGGTA TGGCCAGTAG TGCCAGATTA TGCTCAAATA TCCAGATGC 720 GTGGGACCAG ACCAGCTCAG AAATGCGGGA GATCTATGGA GAGAAATACC TGGCATCCT 780 TCTGAAAAAC CTAAACGAAT TGGACCAGAG GTGCAACAAG GACCTGTCTG TGGTGACTG 840 CTGCATGGAG CACGCTCTGA CTGCCTGTCA CCCTCGCACG AGATACTCAG CTGGCTGGG 900 TGCTAAGCTC TTCTTCACCC CCTTGAGCTA CCTGCCCACC TTTCTTGTGG ATGCTCTTC 960 ATACTGGACT TCTCCAAAAC CTGACAAAGC CCTGTGAAAG CTAGATCCTT TTGTGTTG 1020 GGGTCAATGG AAGTGCTGTG TGAGGGTGCA GANNCTCAGG AGGAGGAAGA TTCCTGTT 1080 CAGCCCACAT GTGCTGTGCA TAGGTGCCTG GCTTTTTCTT CCTCTGTATA ACATGGGG 1140 CATGGGACCA CAGGAATCTG CTATGCTTAA ATGATCATTA CCATTGTTGG TGAAAGAA 1200 AAAACGACCT CCCCTGTCTC GGGTTAAAAA AAAAAAAAAA 1240 1146 base pairs nucleic acid double linear 35 CGCTTGAGAG CTTTCCCCAG AGGCTGCCCT CAGCAGGGCA TCTCATCCCA TCATGTGGCT 60 GCCTCTGCTT CTGGGTGCCT TGCTGTGGGC AGTGCTGTGG TTGCTCAGAG ACCGGCAGA 120 CCTGCCGGCC AGTGATGCTT TCATCTTCAT CACTGGCTGT GACTCTGGCT TTGGGCGCC 180 CCTGGCACTG CAACTTGACC AGAAGGGCTT CCAAGTCCTG GCCGGCTGCC TGACCCCCT 240 TGGAGCAGAA GACCTGCAGC AGATGGCCTC CTCCCGCCTC CACACAACAC TACTGGATA 300 CACTGATCCC CAGAATGTCC AGCAAGTTGC CAAGTGGGTG AAGACACGTG TTGGAGAAA 360 TGGACTTTTT GGTCTGGTGA ATAACGCTGG CGTAGCTGGT ATCATCGGGC CCACACCAT 420 GCTAACACAG GATGATTTCC AGAGAGTACT GAGTGTGAAC ACACTGGGGC CCATCGGTG 480 CACCCTTGCC CTGCTGCCCC TGCTACAGCA GGCCAGGGGT CGGGTGGTCA ACATCACCA 540 TGTCTTGGGC CGCATAGCAG CCAATGGCGG GGGCTACTGT GTCTCCAAGT TTGGCCTGG 600 GGCCTTCTCT GACAGCCTGA GGCGGGACAT GGCTCCGTTC GGAGTACAAG TCTCCATTG 660 GGAGCCTGGC TTCTTTCGAA CCCCTGTGAC CAACCTGGAG AGTCTGGAGA GCACCCTGA 720 GGCTTGTTGG GCCCGGCTAC CTCCAGCTAT ACAGGCCCAC TACGGGGAAG CCTTCCTCG 780 TACTTATCTT CGAGTACAGC GCCGCATCAT GAACCTGATC TGTGACCCAG AACTAACGA 840 GGTGACCAGC TGCCTGGAGC ATGCCCTGAC TGCTCGCCAC CCCCGAACAC GCTACAGCC 900 AGGCTGGGAT GCCAAGCTGC TCTGGCTGCC TGCCTCCTAC CTTCCAGCCA GGGTGGTGG 960 TGCTGTGCTC ACCTGGATCC TTCCCCGGCC CGCCCAGTCA GTCTCCTGAT TCCAGCTT 1020 CAGCAAGAGG CTGATTTTGA AAAGCAAGGC ATCTATTTCT GTGTCTACCC AGTGCTGC 1080 GGTTTCTGAT ACCAATTAGG CTCTCAATAA ATATGTATTG CTTTAAAAAA AAAAAAAA 1140 AAAAAG 1146 316 amino acids amino acid linear 36 Met Trp Leu Tyr Leu Val Ala Leu Val Gly Leu Trp Thr Leu Leu Arg 5 10 15 Phe Phe Arg Glu Arg Gln Val Val Ser His Leu Gln Asp Lys Tyr Val 20 25 30 Phe Ile Thr Gly Cys Asp Ser Gly Phe Gly Asn Leu Leu Ala Arg Gln 35 40 45 Leu Asp Arg Arg Gly Met Arg Val Leu Ala Ala Cys Leu Thr Glu Lys 50 55 60 Gly Ala Glu Gln Leu Arg Asn Lys Thr Ser Asp Arg Leu Glu Thr Val 65 70 75 80 Ile Leu Asp Val Thr Lys Thr Glu Ser Ile Val Ala Ala Thr Gln Trp 85 90 95 Val Lys Glu Arg Val Gly Asn Arg Gly Leu Trp Gly Leu Val Asn Asn 100 105 110 Ala Gly Ile Cys Val Phe Ala Ile Asn Glu Trp Leu Lys Lys Glu Asp 115 120 125 Phe Ala Asn Ile Leu Asp Val Asn Leu Leu Gly Met Ile Glu Val Thr 130 135 140 Leu Ser Met Leu Pro Leu Val Arg Lys Ala Arg Gly Arg Val Phe Asn 145 150 155 160 Ile Ser Ser Ser Met Gly Arg Val Ser Leu Cys Gly Gly Gly Tyr Cys 165 170 175 Ile Ser Lys Tyr Gly Val Glu Ala Phe Ser Asp Ser Leu Arg Arg Glu 180 185 190 Ile Ser Tyr Phe Gly Val Lys Val Ala Ile Ile Glu Pro Gly Gly Phe 195 200 205 Arg Thr Asn Val Ser Asn Tyr Glu Arg Leu Ser His Ser Ile Glu Lys 210 215 220 Leu Trp Asp Gln Thr Ser Ser Glu Val Lys Glu Val Tyr Asp Lys Asn 225 230 235 240 Phe Leu Asp Ser Tyr Ile Lys Ala Ile Gln Ser Leu Thr Asp Thr Cys 245 250 255 Ser Asp Asp Leu Ser Val Val Thr Asp Cys Met Glu His Ala Leu Thr 260 265 270 Ala Cys His Pro Arg Thr Arg Tyr Ser Ala Gly Trp Asp Ala Lys Leu 275 280 285 Phe Tyr Leu Pro Leu Ser Tyr Met Pro Thr Phe Leu Val Asp Ala Met 290 295 300 Leu Tyr Trp Ser Ser Val Lys Pro Ala Gln Ala Leu 305 310 315 317 amino acids amino acid linear 37 Met Trp Leu Tyr Leu Val Ala Leu Val Gly Leu Trp Thr Leu Leu Arg 5 10 15 Phe Phe Arg Val Arg Gln Val Val Ser His Leu Gln Asp Lys Tyr Val 20 25 30 Phe Ile Thr Gly Cys Asp Ser Gly Phe Gly Thr Leu Leu Ala Arg Gln 35 40 45 Leu Asp Arg Arg Gly Met Arg Val Leu Ala Ala Cys Leu Thr Glu Lys 50 55 60 Gly Ala Glu Glu Leu Arg Asn Lys Thr Ser Asp Arg Leu Glu Thr Val 65 70 75 80 Ile Leu Asp Val Thr Lys Thr Glu Ser Ile Val Thr Ala Thr Gln Trp 85 90 95 Val Lys Glu His Val Gly Asn Arg Gly Leu Trp Gly Leu Val Asn Asn 100 105 110 Ala Gly Ile Ser Thr Pro Ser Gly Pro Asn Glu Trp Met Lys Lys Gln 115 120 125 Asp Phe Ala His Val Leu Asp Val Asn Leu Leu Gly Met Ile Glu Val 130 135 140 Thr Leu Ser Met Leu Pro Leu Val Arg Lys Ala Arg Gly Arg Val Val 145 150 155 160 Asn Val Ser Ser Val Met Gly Arg Val Ser Leu Phe Gly Gly Gly Tyr 165 170 175 Cys Ile Ser Lys Tyr Gly Val Glu Ala Phe Ser Asp Ser Leu Arg Arg 180 185 190 Glu Leu Arg Tyr Phe Gly Val Lys Val Ala Ile Ile Glu Pro Gly Phe 195 200 205 Phe Leu Thr Gly Val Thr Ser Ser Ala Arg Leu Cys Ser Asn Thr Gln 210 215 220 Met Leu Trp Asp Gln Thr Ser Ser Glu Ile Arg Glu Ile Tyr Gly Glu 225 230 235 240 Lys Tyr Leu Ala Ser Tyr Leu Lys Arg Leu Asn Lys Leu Asp Lys Arg 245 250 255 Cys Asn Lys Asp Leu Ser Gly Val Thr Asp Cys Met Glu His Ala Leu 260 265 270 Thr Ala Cys His Pro Arg Thr Arg Tyr Ser Ala Gly Trp Asp Ala Lys 275 280 285 Leu Phe Tyr Leu Pro Leu Ser Tyr Leu Pro Thr Phe Leu Val Asp Ala 290 295 300 Leu Leu Tyr Trp Thr Ser Leu Arg Pro Glu Lys Ala Leu 305 310 315 318 amino acids amino acid linear 38 Met Trp Leu Tyr Met Val Ala Leu Leu Gly Leu Trp Met Leu Leu Arg 5 10 15 Phe Phe Arg Glu Arg Gln Val Val Asp His Leu Gln Asp Lys Tyr Val 20 25 30 Phe Ile Thr Gly Cys Gly Ser Gly Phe Gly Asn Leu Leu Ala Arg Gln 35 40 45 Leu Asp Arg Arg Gly Met Arg Val Leu Ala Ala Cys Arg Lys Glu Glu 50 55 60 Gly Ala Glu Glu Leu Arg Arg Lys Thr Ser Glu Arg Leu Glu Thr Val 65 70 75 80 Ile Leu Asp Val Thr Lys Thr Glu Asn Ile Val Ala Ala Thr Gln Trp 85 90 95 Val Lys Glu Arg Val Gly Asn Arg Gly Leu Trp Gly Leu Val Asn Asn 100 105 110 Ala Gly Ile Ser Val Pro Ser Gly Pro Asn Glu Trp Met Lys Lys Gln 115 120 125 Asp Phe Ala Ser Val Leu Asp Val Asn Leu Leu Gly Leu Ile Glu Val 130 135 140 Thr Leu Ser Met Leu Pro Leu Val Arg Lys Ala Arg Gly Arg Val Val 145 150 155 160 Asn Val Ser Ser Ile Leu Gly Arg Val Ser Leu Gly Gly Ser Gly Gly 165 170 175 Tyr Cys Ile Ser Lys Tyr Gly Ile Glu Ala Phe Ser Asp Ser Leu Arg 180 185 190 Arg Asp Val Arg Tyr Phe Gly Val Lys Val Ala Ile Ile Glu Pro Gly 195 200 205 Phe Phe Leu Thr Gly Met Ala Ser Ser Ala Arg Leu Cys Ser Asn Ile 210 215 220 Gln Met Leu Trp Asp Gln Thr Ser Ser Glu Met Arg Glu Ile Tyr Gly 225 230 235 240 Glu Lys Tyr Leu Ala Ser Tyr Leu Lys Asn Leu Asn Glu Leu Asp Gln 245 250 255 Arg Cys Asn Lys Asp Leu Ser Val Val Thr Asp Cys Met Glu His Ala 260 265 270 Leu Thr Ala Cys His Pro Arg Thr Arg Tyr Ser Ala Gly Trp Asp Ala 275 280 285 Lys Leu Phe Phe Thr Pro Leu Ser Tyr Leu Pro Thr Phe Leu Val Asp 290 295 300 Ala Leu Leu Tyr Trp Thr Ser Pro Lys Pro Asp Lys Ala Leu 305 310 315 318 amino acids amino acid linear 39 Met Trp Leu Pro Leu Leu Leu Gly Ala Leu Leu Trp Ala Val Leu Trp 5 10 15 Leu Leu Arg Asp Arg Gln Ser Leu Pro Ala Ser Asp Ala Phe Ile Phe 20 25 30 Ile Thr Gly Cys Asp Ser Gly Phe Gly Arg Leu Leu Ala Leu Gln Leu 35 40 45 Asp Gln Lys Gly Phe Gln Val Leu Ala Gly Cys Leu Thr Pro Ser Gly 50 55 60 Ala Glu Asp Leu Gln Gln Met Ala Ser Ser Arg Leu His Thr Thr Leu 65 70 75 80 Leu Asp Ile Thr Asp Pro Gln Asn Val Gln Gln Val Ala Lys Trp Val 85 90 95 Lys Thr Arg Val Gly Glu Thr Gly Leu Phe Gly Leu Val Asn Asn Ala 100 105 110 Gly Val Ala Gly Ile Ile Gly Pro Thr Pro Trp Leu Thr Gln Asp Asp 115 120 125 Phe Gln Arg Val Leu Ser Val Asn Thr Leu Gly Pro Ile Gly Val Thr 130 135 140 Leu Ala Leu Leu Pro Leu Leu Gln Gln Ala Arg Gly Arg Val Val Asn 145 150 155 160 Ile Thr Ser Val Leu Gly Arg Ile Ala Ala Asn Gly Gly Gly Tyr Cys 165 170 175 Val Ser Lys Phe Gly Leu Glu Ala Phe Ser Asp Ser Leu Arg Arg Asp 180 185 190 Met Ala Pro Phe Gly Val Gln Val Ser Ile Val Glu Pro Gly Phe Phe 195 200 205 Arg Thr Pro Val Thr Asn Leu Glu Ser Leu Glu Ser Thr Leu Lys Ala 210 215 220 Cys Trp Ala Arg Leu Pro Pro Ala Ile Gln Ala His Tyr Gly Glu Ala 225 230 235 240 Phe Leu Asp Thr Tyr Leu Arg Val Gln Arg Arg Ile Met Asn Leu Ile 245 250 255 Cys Asp Pro Glu Leu Thr Lys Val Thr Ser Cys Leu Glu His Ala Leu 260 265 270 Thr Ala Arg His Pro Arg Thr Arg Tyr Ser Pro Gly Trp Asp Ala Lys 275 280 285 Leu Leu Trp Leu Pro Ala Ser Tyr Leu Pro Ala Arg Val Val Asp Ala 290 295 300 Val Leu Thr Trp Ile Leu Pro Arg Pro Ala Gln Ser Val Ser 305 310 315 22 base pairs nucleic acid single linear 40 CTCAGGCTGT CAGAGAAGGC CT 22 19 base pairs nucleic acid single linear 41 GACGATTTCC AGCGGGTGC 19 

1. Isolated nucleic acid molecule which codes for a mammalian protein having a molecular weight of about 32 kilodaltons as determined by SDS-PAGE, wherein said protein complexes with retinol binding protein receptor having a molecular weight of about 63 kilodaltons as determined by SDS-PAGE, wherein the complement of said isolated nucleic acid molecule hybridizes to the nucleotide sequence of SEQ ID NO:10 under stringent conditions.
 2. The isolated nucleic acid molecule of claim 1, wherein said mammalian protein is human protein.
 3. The isolated nucleic acid molecule of claim 1, wherein said mammalian protein is murine protein.
 4. The isolated nucleic acid molecule of claim 1, comprising cDNA.
 5. The isolated nucleic acid molecule of claim 1, comprising genomic DNA.
 6. The isolated nucleic acid molecule of claim 2, consisting of SEQ ID NO:14.
 7. The isolated nucleic acid molecule of claim 2, which encodes the amino acid sequence of SEQ ID NO:15.
 8. The isolated nucleic acid molecule of claim 2, which encodes the amino acid sequence of SEQ ID NO:15.
 9. The isolated nucleic acid molecule of claim 3, which encodes the amino acid sequence of SEQ ID NO:29.
 10. Expression vector comprising the isolated nucleic acid molecule of claim 1, operably linked to a promoter.
 11. Expression vector comprising the isolated nucleic acid molecule of claim 2, operably linked to a promoter.
 12. Cell line or bacterial cell strain, transformed or transfected with the expression vector of claim
 10. 13. Cell line or bacterial cell strain, transformed or transfected with the expression vector of claim
 11. 14. Isolated nucleic acid molecule which encodes a protein having retinol dehydrogenase activity, the complementary sequence of which hybridizes, under stringent conditions, to at least one nucleic acid molecule, selected from the group consisting of SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22 and SEQ ID NO:23, and sequences complementary thereto.
 15. The isolated nucleic acid molecule of claim 14, selected from the group consisting SEQ ID NOS:20, 21, 22 and
 23. 